Steerable medical devices, systems, and methods of use

ABSTRACT

Steerable medical devices and methods of use. In some embodiments, the steerable medical devices can be steered bi-directionally. In some embodiments the steerable medical devices include a first flexible tubular member and a second flexible tubular member secured together at a location distal to a steerable portion of the steerable medical device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the priority of U.S. Provisional App. Ser. No.62/152,741, filed Apr. 24, 2015, which is incorporated by referenceherein.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

BACKGROUND

Steerable medical devices can be used in any application when a medicaldevice needs to be steered, or bent. For example, steerable deliverydevices can be used to deliver, or guide, medical devices or instrumentsto a target location within a subject. The delivery devices provideaccess to target locations within the body where, for example,diagnostic, therapeutic, and interventional procedures are required.Access via these devices is generally minimally invasive, and can beeither percutaneous, or through natural body orifices. The access canrequire providing a guiding path through a body lumen, such as, forexample without limitation, a blood vessel, an esophagus, a trachea andadjoining bronchia, ducts, any portion of the gastro intestinal tract,and the lymphatics. Once a delivery device has provided access to thetarget location, the delivery device is then used to guide the medicaldevice or instrument to perform the diagnostic, therapeutic, orinterventional procedure. An example of such a delivery device is aguide catheter, which may be delivered by steering it to its requireddestination, tracking it along a previously delivered guide wire, orboth. The list of components being delivered for use percutaneously islarge and rapidly growing.

Minimal outer dimensions of delivery devices can be important forminimizing the injury associated with delivery. Minimizing the wallthickness of a delivery device provides additional space for the medicaldevice to be guided, while minimizing the injury associated with entryinto the subject and the closure needed. Flexibility of a deliverydevice is important in allowing the guiding device to track or besteered to its target destination along tortuous paths while minimizinginjury to the intervening tissues. A delivery device may also need tohave compressive and tensile properties sufficient to support itsdelivery to the target site. When tracking around bends in the body, anykinks created in a guiding device can create an obstruction to thedelivery of the medical device. When used as a steerable device, thedistal end of a delivery device is preferably deflectable over a rangeof bend radii and responsive to the steering controls. A delivery devicemay also need to support torque transmitted from the handle to thedistal region.

Once a delivery device is in place the delivery device preferably alsosupports torque around a distal bend such that the medical device may berotated into position while sustaining some contact loads. Additionally,once in place the guiding device preferably is sufficiently stiff tosupport and guide the medical device to its target destination. Aguiding device may also remain stable and not shift from one state ofequilibrium to another either spontaneously or under the influence offorces being imparted to it from the delivery of the medical device orits own control mechanisms. As a delivery device often travels downfluid-filled lumens such as, for example without limitation, bloodvessels, it should additionally incorporate a seal against fluidsimpinging upon its periphery and another at its distal end whichinterfaces with the medical device to maintain a seal around thedelivery device.

There exists a need for improved steerable medical devices, such assteerable delivery devices.

SUMMARY OF THE DISCLOSURE

One aspect of the disclosure is a steerable medical device, comprisingan inner flexible tubular member with an inner spine; an outer flexibletubular member axially fixed to the inner flexible tubular member at afixation location distal to a steerable portion, the outer tubularmember having an outer spine that is offset from the inner spine, and alinear reinforcing member extending within the outer spine; and anexternal controller operatively interfacing with the inner and outerflexible tubular members to put one of the inner and outer tubularmembers in tension and the other in compression, to steer the steerableportion.

In some embodiments the inner tubular member further comprises an innerlinear reinforcing member extending within the inner spine. The linearreinforcing member and the inner linear reinforcing member can be 180degrees away around the steerable medical device.

In some embodiments the linear reinforcing member is 180 degrees awayfrom the inner spine around the steerable medical device.

In some embodiments the outer spine comprises a linear segment of firstmaterial extending less than 180 degrees around the outer tubularmember. The first material can have a durometer greater than a secondsegment of material extending more than 180 degrees around the outertubular member.

In some embodiments the outer tubular member further comprises a braidedreinforcing member in the steerable portion. The linear reinforcingmember can be woven into the braided reinforcing member.

In some embodiments a distal end of the linear reinforcing member isfurther distally than a distal end of the steerable portion. A distalend of the linear reinforcing member can extend substantially to adistal end of the outer tubular member.

In some embodiments a distal end of the linear reinforcing memberextends to a location where the inner tubular member and outer tubularmember are axially secured together.

One aspect of the disclosure is a steerable medical apparatus,comprising: an external controller comprising an actuator and a drivingmember; and an elongate steerable device including first and secondtubular members axially fixed to one another at a location distal to asteerable portion, one of the first and second tubular members withinthe other, a proximal end of the first tubular member operatively fixedto the driving member such that axial movement of the driving membercauses axial movement of a proximal end of the first tubular member, theactuator operatively interfaced with the driving member such that inresponse to actuation of the actuator in a first direction, the drivingmember moves proximally, the first tubular member is put in tension andthe second tubular member is put in compression, and the steerableportion is steered in first direction, and in response to actuation ofthe actuator in a second direction opposite the first direction, thedriving member moves distally, the first tubular member is put incompression and the second tubular member is put in tension, and thesteerable portion is steered in a second direction different than thefirst direction.

In some embodiments the first tubular member is an outer tubular member,the second tubular member being an inner tubular member within thetubular member.

In some embodiments the actuator is coupled to a nut, and the nutinterfaces the driving member.

In some embodiments the driving member comprises an external thread, theactuator operatively interfaced with the external thread. The actuatorcan be coupled to a nut, and wherein the nut can interface the externalthread. In some embodiments the actuator operatively interfaces with theexternal thread at a location axially spaced from a proximal-most endand a distal-most end of the thread. The proximal end of the firsttubular member can be fixed to the driving member within a lumen of thedriving member. The second tubular member can be disposed within thelumen of the driving member.

In some embodiments a proximal end of the second tubular member isaxially fixed to a component of the external controller that is notconfigured to move axially when the driving member moves axially. Insome embodiments the proximal end of the second tubular member isaxially fixed to a valve body.

In some embodiments the driving member interfaces a handle shell with afemale and male interface that prevents rotation of the driving memberin response to actuation of the actuator.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a steerable portion of a steerablemedical device.

FIGS. 2A, 2B, and 2C illustrate steering of exemplary steerable portionsof steerable medical devices.

FIG. 3 illustrates a flattened view showing an exemplary slot patternfor use in a steerable portion of a device.

FIG. 4 illustrates a flattened view showing an exemplary slot patternfor use in a steerable portion of a device.

FIG. 5 illustrates a flattened view showing an exemplary slot patternfor use in a steerable portion of a device.

FIG. 6 illustrates a flattened view showing an exemplary slot patternfor use in a steerable portion of a device.

FIGS. 7A and 7B illustrate flattened views showing exemplary slotpatterns for use in a steerable portion of a device.

FIG. 8 illustrates an exemplary steerable portion including an outerslotted tubular member and an inner slotted tubular member, with anintermediate tubular element therebetween.

FIG. 9 illustrates an exemplary steerable portion including an outerslotted tubular member and an inner non-slotted tubular member.

FIG. 10 illustrates an exemplary steerable portion including an innerslotted tubular member and outer non-slotted tubular member.

FIG. 11A is a representation of a pattern for use in a steerable portioncapable of being cut from a tube or created by winding a ribbon into atube.

FIG. 11B illustrates a section of a ribbon for use in the tube of FIG.11A.

FIGS. 12A and 12B are different views of a groove pattern for use in asteerable portion.

FIGS. 13A, 13B, and 13C are various views of a cut pattern for use in aguide catheter.

FIG. 14 illustrates an outer guide member and a steerable devicetherein.

FIG. 15 illustrates a discontinuous cut pattern for use on a tubularmember that is most steerable in compression.

FIGS. 16A and 16B illustrate a portion of a tubular member formed withthe cut pattern from FIG. 15, while FIG. 16C illustrates compressive andtensile forces acting thereon.

FIG. 17 is a graph illustrating Force v. Displacement behaviorassociated with the application of loads or displacements at variouspoints around the tubular member shown in FIGS. 15-16C.

FIG. 18 illustrates a continuous cut pattern for use on a tubular memberthat is most steerable in tension.

FIG. 19 illustrates a discontinuous cut pattern for use on a tubularmember most steerable in tension.

FIG. 20 illustrates a continuous cut pattern for use on a tubular membermost deflectable in tension.

FIG. 21 illustrates a discontinuous cut pattern for use on a tubularmember with a substantially straight, continuous spine.

FIG. 22 illustrates a discontinuous cut pattern for use on a tubularmember with a helical, continuous spine.

FIG. 23 is a flattened view of an exemplary tubular member with morethan one spines.

FIG. 24 is a flattened view of an exemplary member with a singlesubstantially straight spine.

FIG. 25 illustrates a flattened portion of an exemplary tubular member.The slots create a relatively neutral pattern.

FIG. 26 illustrates a flattened portion of an exemplary tubular memberincluding interlocking features with complimentary curved surfaces thatare adapted to support rotation of the tubular member.

FIG. 27 illustrates an exemplary steerable delivery device including afloating tubular member disposed therein.

FIG. 28 illustrates an exemplary steerable medical system.

FIGS. 29, 30, 31, 32, 33 and 34 illustrate different views of anexemplary steerable medical device.

FIG. 35 illustrates a representation of the performance of the device inFIGS. 29-34.

FIG. 36 illustrates an embodiment of a cut-out pattern incorporatingboth controlled variation in bending stiffness and features whichenhance torsional stiffness.

FIG. 37 illustrates inner and outer tubular members rotated relativelyto one another thereby causing the bent distal end of the sheath torotate in a generally circular arc.

FIG. 38 illustrates an exemplary steerable device with an externalactuator.

FIGS. 39, 40 and 41 illustrate different views of an exemplary externalcontroller.

FIGS. 42A-42G illustrate an exemplary embodiment of a portion of asteerable device that includes materials with different durometers.

FIGS. 43A-43D illustrate an exemplary embodiment of a portion of asteerable device that includes materials with different durometers.

FIGS. 44A-44C illustrate an exemplary inner tubular member. FIG. 44A isa top view. FIG. 44B is a view rotated 90 degrees relative to the FIG.44A view, and FIG. 44C is a view rotated 180 degrees relative to theview in FIG. 44A (and 90 degrees relative to the view in FIG. 44B).

FIGS. 45A-45C illustrate an exemplary outer tubular that is part of asteerable device and is disposed outside of and around an inner tubularmember from FIGS. 44A-44C. FIG. 45A is a top view. FIG. 45B is a viewrotated 90 degrees from the view in FIG. 45A, and FIG. 45C is a viewrotated 180 degrees from the view in FIG. 45A (and 90 degrees from theview in FIG. 45B).

FIGS. 46A-46E illustrate views of an assembly including the inner andouter tubular members from FIGS. 44 and 45.

FIGS. 47A-47I illustrate an exemplary inner tubular member.

FIGS. 48A-48D illustrate an exemplary outer tubular member.

FIGS. 49A-49D illustrate a steerable device comprising the inner andouter tubular members from FIGS. 47A-47I and FIGS. 48A-48D.

FIGS. 50A and 50B are side views of an exemplary inner tubular member,including an exemplary angled seam.

FIG. 50C is a side view of an exemplary inner tubular member, with cutout at select portions to illustrate some components of the innertubular member.

FIG. 50D is a side view of a portion of an exemplary inner tubularmember.

FIG. 50E is a section view of an exemplary inner tubular member shown inFIG. 50D.

FIGS. 51A and 51B illustrate flexing, or bending, of an exemplarysteerable medical device.

FIG. 52A is a side view showing a portion of an exemplary steerablemedical device.

FIG. 52B is a section view of a portion of an exemplary steerablemedical device shown in FIG. 52A.

FIG. 52C is a section view of an exemplary steerable medical deviceshown in FIG. 52A.

FIG. 52D shows a detail view of a distal end of an exemplary steerablemedical device.

FIG. 53A is a perspective view of an exemplary steerable medical device,including a steerable sheath and an external controller.

FIG. 53B is an exploded view of the exemplary external controller shownin FIG. 53A.

FIGS. 54A, 54B, and 54C illustrate an exemplary outer tubular member.

FIGS. 55A, 55B, 55C, and 55D illustrate exemplary bonding of inner andouter tubular members.

FIGS. 56A, 56B, 56C, 56D, 56E, 56F, 56G, and 56H illustrate an exemplaryhandle that can impart bi-directionality to a steerable medical device.

DETAILED DESCRIPTION

The disclosure relates generally to steerable medical devices, includingsteerable guide devices, and their methods of use. When a steerablemedical “delivery” device is described herein it is merely an example ofthe steerable medical devices described herein. Steerable deliverydevices can be used to deliver, or guide, any type of suitable medicaldevice or instrument therethrough to a target location within apatient's body. For example, a steerable delivery device can be used todeliver, or guide, a medical device into bodily lumens or cavities suchas, for example without limitation, a blood vessel, an esophagus, atrachea and possibly adjoining bronchia, any portion of thegastrointestinal tract, an abdominal cavity, a thoracic cavity, variousother ducts within the body, the lymphatics, one or more chambers of theheart, etc. Once a steerable delivery device has gained access to atarget location within the subject, one or more medical devices orinstruments is delivered, or guided, to the target location to carry outone or more medical interventions. In some methods of use steerabledelivery device described herein are tracked along a previouslypositioned guide wire, the positioning of which is known in the art. Insome embodiments the steerable concepts described herein can be appliedto steerable medical devices such as catheters that have any diagnosticand/or therapeutic functionality, and which are advanced through aseparate guide device.

FIG. 1 is a perspective view of a distal portion of an exemplarysteerable delivery device. Steerable device 10 includes steerableportion 12 and has distal end 15. Steerable portion 12 includes an outertubular member 14 and inner tubular member 16. Outer tubular member 14has an inner surface defining a lumen therein, and inner tubular member14 is sized to be disposed within the inner lumen of outer tubularmember 14. Outer tubular member 14 and inner tubular member 16 arepermanently axially fixed relative to one another at fixation location18 along the length of steerable device 10. That is, at fixationlocation 18, the inner and outer tubular members are not adapted to movedistally or proximally relative to one another and are permanentlyaxially fixed to one another. “Permanent” fixation as used hereingenerally refers to fixation that occurs during manufacture of thedevice such that one or more components are not adapted or intended tobe disengaged from one another during use of the device. As used herein,when the tubular members or components are described as being axiallyfixed relative to one another at a certain location, the fixation can bepermanent fixation or temporary fixation unless specifically indicatedto be one or the other. Fixation location 18 is located distal tosteerable portion 12. At locations proximal to fixation location 18,inner tubular member 16 and outer tubular member 14 are axially movablerelative to one another. That is, along steerable portion 12, innertubular member 16 and outer tubular member 14 are adapted to moveaxially relative to another, which provides for the steering of thedevice, described below. Outer tubular member 14 has slots 22 formedtherein, which define spine 20. Spine 20 extends along a length ofsteerable portion 12. Slots 22 are shown substantially perpendicular tothe longitudinal axis “L” of steerable portion 12, when steerableportion 12 is in a straightened configuration as shown in FIG. 1. Innertubular member 16 also has slots formed therein (not shown) in thesteerable portion, which define a spine (not shown).

FIGS. 2A and 2B illustrate an exemplary embodiment of a steerabledelivery device. Steerable device 30 has a distal end 37 and includesouter tubular element 34 and inner tubular element 36 which are axiallyimmovable relative to one another at fixation location 38, but areaxially movable proximal to fixation location 38. Outer tubular element34 includes a plurality of slots 42 formed therein to define spine 40.Inner tubular element 36 also includes a plurality of slots formedtherein (not shown) to define a spine (not shown). In FIGS. 2A and 2B,the spines are disposed substantially 180 degrees apart from oneanother. FIG. 2A illustrates steerable portion 32 deflected, or steered,into a first bent configuration, while FIG. 2B illustrates steerableportion 32 steered into a second bent configuration different than thefirst bent configuration. To steer the steerable portion into theconfiguration shown in FIG. 2A, a proximal portion of outer tubularmember 34 is moved axially, and specifically proximally, relative toinner tubular member 36, while the tubular elements 34 and 36 areaxially fixed relative to one another at fixation location 38. This canbe accomplished by pulling outer tubular member 23 in a proximal “P”direction while maintaining the position of inner tubular member 36, bypushing inner tubular member 36 in a distal “D” direction whilemaintaining the position of outer tubular member, or by a combinationthereof. The relative axial movement of the inner and outer tubularmembers as shown in FIG. 2A applies substantially opposing compressiveand tensile forces to the spines of the tubular members, thusdeflecting, or steering, the device in the direction of spine 40 ofouter tubular member 34, as is shown in FIG. 2A. FIG. 2B illustrates astep of steering device 30 in the substantially opposite direction fromthat shown in FIG. 2A. To steer device 30 into the configuration shownin FIG. 2B, inner tubular member is moved proximally relative to outertubular member 34. This can be performed by moving the outer tubularmember distally, moving the inner tubular member proximally, or acombination thereof. This relative axial movement applies substantiallyopposing compressive and tensile forces to the spines in steerableportion 32 of device 30, thereby deflecting the device in a directionsubstantially opposite that of spine 40 of outer tubular member 34.

FIG. 2C shows a sectional view of the steerable portion from FIG. 2B,including optional floating tubular member 505 disposed within innertubular member 504. Steerable portion 500 includes inner tubular member504 and outer tubular member 502. Inner tubular member 504 hasinterrupted slots 512 formed therein to define spine 506. Outer tubularmember 502 has interrupted slots 510 formed therein to define spine 508.The steerable portion is bent along the axis of spine 506. Spine 508 andspine 506 are substantially 180 degrees apart from one another (i.e.,they are on substantially opposite sides of steerable portion 500).

To steer steerable portion 500 into the configuration shown in FIG. 2C(also shown in FIG. 2B), inner tubular member 504 is pulled in theproximal direction relative to outer tubular member 502, as isillustrated in FIG. 2B. Pulling on the inner member 504 applies atensile force to inner spine 506. Because inner and outer tubularmembers 504 and 502 are axially fixed relative to one another at alocation distal to the steerable portion, pulling on inner member 504relative to outer tubular member 502 results in a compressive forceapplied to the distal end of the steerable portion of outer tubularmember 502. The compressive force begins to compress slots 510 on outertubular member 502. Compression of outer slots 510 causes outer tubularmember to bend in the direction shown in FIG. 2C, and the bending stopswhen inner slots 510 are closed. Thus, outer slots 510 limit the degreeof the bend of steerable portion 500. The same type of bending that isshown in FIGS. 2B and 2C would occur if outer tubular element 502 werepushed distally relative to inner tubular member 504.

If outer tubular member 502 were pulled proximally relative to innertubular member 504 (or if inner tubular member 504 were pushed distallyrelative to outer tubular member 502), steerable portion 500 would bendin the manner shown in FIG. 2A. The degree of the bend would be limitedby inner slots 512.

FIG. 2C illustrates an embodiment of a medical device including afloating tubular member, which may be referred to herein as a floatingliner. In general, a floating liner is disposed within an outerstructure. In the exemplary embodiment in FIG. 2C, the outer structureincludes the inner and outer tubular members. The outer structuregenerally provides structural and mechanical properties for the deliverydevice, and the floating liner provides lubricity for a medical deviceor instrument to be advanced therethrough. A floating liner is generallyimpermeable as well. A floating liner “floats” with a portion of theouter structure. That is, the floating liner is not fixed to a portionof the outer structure in which it floats. In the exemplary embodimentin FIG. 2C, the floating liner floats within the steerable portion(i.e., is not attached to the steerable portion). In general, a floatingliner is attached to the outer structure at a location proximal to thesteerable or bendable portion of the device. For example, in theembodiment in FIG. 2C, the floating liner is attached to the outerstructure at a location proximal to the steerable portion. A floatingliner doesn't impede the ability of the outer structure to move as it issteered, bent, actuated, receives forces applied thereto, etc.

In some embodiments the floating liner is a lubricious polymer tube. Insome embodiments the floating liner includes wire windings and/oraxially laid wires.

The outer structure in which the floating liner floats can be anysuitable tubular member. For example, the outer structure can be acatheter, guiding device, a steerable device, etc. In some embodimentsthe outer structure has a neutral bending preference but is not intendedto be steered. In this embodiment the outer structure provides axial andradial stiffness thereby limiting the likelihood of kinks while thefloating liner provides lubricity and is additionally restrained fromkinking by the outer structure.

FIGS. 2A and 2B also show proximal portion 35 of device 30, which isproximal to steerable portion 32, having a substantially neutral portiondesigned to have no preferential bending axis while at the same timetransmitting axial force and torque applied at a proximal end of thedevice (not shown).

In some embodiments, the inner and outer tubular members are adapted tohave opposing compressive and tensile loads applied thereto to steer thesteerable portion. In some embodiments at least one of the tubularmembers has a neutral bending axis. A neutral bending axis, as usedherein, generally refers to an axis of the tubular member along whichthere is substantially no axial displacement in response to acompressive and/or tensile force applied thereto. Axial displacementalong the neutral bending axis, in response to a compressive and/ortensile force applied thereto, is less than axial displacement ofstructures elsewhere in the tubular member. In particular, axialdisplacement along the neutral bending axis is minimal relative to axialdisplacement of structures elsewhere in the tubular member. Examples ofa neutral bending axis include spine 382 in FIG. 21 and spines 412 and414 in FIG. 23.

In some embodiments at least one of the tubular members is adapted tooffset the neutral bending axis relative to the opposite tubular member.The neutral bending axes of the tubular members can be offset to beapproximately tangent to opposite sides of the opposing members, makingthe neutral bending axis offset equal to the diameter of the device,thus providing the highest possible bending leverage ratio for a givendevice diameter.

The tubular members described herein may exhibit preferential or neutralbending behavior. Neutral bending behavior implies that the displacementfor a given radially applied load (from the edge of the tubular memberthrough the longitudinal axis of the tubular member) will be independentof the radial angle from which the load was applied. In contrast, in anon-neutral structure the displacement associated with a radial loadwill change as a function of the radial angle. An exemplary tubularmember tending towards neutral bending behavior is shown in FIG. 25 orthe uninterrupted spiral pattern of FIG. 25 which is essentially aspring.

In some embodiments the inner and outer tubular elements are adapted tobe rotated relative to one another to enhance the steerability of thesteerable portion. The tubular elements can rotate relative to oneanother yet remain axially fixed relative to one another at a locationdistal to the steerable portion. In these embodiments, in addition toaxial forces being applied to one or more tubes, one or more tubularmembers are also rotated with respect to each other to steer thesteerable portion.

In some embodiments only one of the inner and outer tubular members hasat least one slot defining a spine along the steerable portion, whilethe other does not have any slots along the steerable portion. Forexample, in FIGS. 2A and 2B, outer tubular member 34 can have a slot anda spine while inner tubular member 36 does not have a slot formedtherein. Alternatively, inner tubular member 36 can have at least oneslot and a spine while outer tubular member 34 does not have a slotformed therein. The steerable portion can be steered as described hereinif at least one of the inner and outer tubular members is adapted topreferentially bend in a first direction.

In the embodiment in FIGS. 1 and 2 the slots in both tubular members aresubstantially perpendicular to the longitudinal axis of the steerableportion. The slots in one or both of the tubular members can be,however, at an angle relative to the longitudinal axis that is otherthan substantially 90 degrees.

In some embodiments the steerable device also includes a tubular elementdisposed between the inner and outer tubular members. The intermediatemember can be, for example without limitation, a flexible polymericmaterial. The intermediate member can be encasing one or both of thetubular members, or comprising one or both of the members. Theintermediate member can be adapted to provide a fluid barrier and/or alow friction surface.

Slots as described herein can be formed in a tubular member by lasermachining or other machining processes. Forming the slots creates atleast one spine in a tubular member. A spine as used herein can beconsidered a region of the steerable portion that imparts axialstiffness in compression or tension, or both, and may additionallyinclude features that provide torsional stiffness. When a single spineis created in a tubular member, the neutral bending axis of the tubularmember is moved to the spine of the tubular member.

In some embodiments, a tubular member includes at least two spines, thecombination of which moves the neutral bending axis of the tubularmember to an axis parallel to, or tangent to when bent, the longitudinalaxis of the tubular device and passing through the spines.

In some embodiments a liner, such as a flexible polymer liner, is bondedon the inner surface of the inner tubular member. In some embodiments aflexible polymer is bonded or otherwise disposed over the outer surfaceof the outer tubular member. A liner can also be disposed such that itis encasing the inner tubular member.

In some embodiments the steerable portion is comprised of a firsttubular member that is adapted to bend preferentially in a firstdirection and a second tubular member that is not adapted to bendpreferentially in one direction. In some instances of these embodiments,the second tubular member is a flexible polymer material with or withouta braided or wire support. In some instances, a wire or other structuralsupport is included in the first tubular member in the deflectable areato increase compressive and tensile stiffness along one side of thetubular member, thus moving the neutral bending axis from thelongitudinal axis of the tubular member to the side of the tubularmember that includes the structural support. In some instances wires arelaid longitudinally and distributed evenly to increase axial stiffnessin tension without creating a preferential bending.

In some embodiments the device includes three tubular members, havingthree offset neutral bending axes approximately 120 degrees radiallyspaced apart, thus providing the steerable device with universalsteering in any direction.

FIG. 3 illustrates, for ease of description, a flattened, or unrolled,portion of exemplary tubular member 50, which can be an inner or anouter tubular member. Tubular member 50 includes fixation region 52,steerable portion 54, and a proximal neutral portion 58. Steerableportion 54 includes a plurality of slots 56 formed therein to definespine 55 extending along the steerable portion. Slots 56 aresinuous-shaped slots, and spine 55 has a generally straightconfiguration along the length of steerable portion 54. That is, spine55 is substantially parallel with the longitudinal axis of the tubularmember. Fixation region 52 includes a plurality of holes 57 tofacilitate bonding to provide for axial fixation relative to a secondtubular member (not shown). Proximal portion 58 includes a plurality ofmultiple overlapping slots 60 to provide the desired flexibility, axialforce transmission, and torque transmission characteristics.

FIG. 4 illustrates a flattened, or unrolled, portion of exemplarytubular member 61, which can be an inner or an outer tubular member of asteerable portion. Tubular member 61 includes fixation region 62,steerable portion 64, and proximal neutral bending portion 68. Neutralbending portion 68 will exhibit minimal bending preference upon acompressive or tensile force applied thereto. Tubular member 61 issimilar to tubular member 50 shown in FIG. 3, but includes linkingelements 72, which can be flexible. Each linking element extends fromone side of a slot to the other side. Each linking element includes twoarm portions extending from one side of the slot to the other side ofthe slot. The two arms meet at the point at which they are connected toone side of the slot. The linking elements extend along steerableportion 64 on substantially the opposite side as spine 65. Linkingelements 72 enhance and/or control torque response and bending ofsteerable portion 64. As steerable portion 64 is bent about spine 65,linking elements 72 bend and stretch under tension. As steerable portion64 is twisted, or put in torque, linking elements 72 are put incompression. In torque, the gap between a given linking element and thesection of the tubular member proximally adjacent to the given linkingelement collapses, effectively increasing the torsional stiffness ofsteerable portion 64.

FIG. 5 illustrates a flattened portion of exemplary tubular member 80,including fixation portion 82, steerable portion 84, and proximalneutral portion 86. The embodiment in FIG. 5 is similar to the outertubular member as shown in FIGS. 2A and 2B. Steerable portion 84includes substantially straight slots 90 that are substantiallyperpendicular to the longitudinal axis of tubular member 80. Spine 88 issubstantially straight in configuration, extending along the length ofsteerable portion 84 substantially parallel to the longitudinal axis ofthe tubular member 80. Fixation portion 82 includes holes 92therethrough (four shown) to facilitate bonding. Proximal portion 86 hasmultiple overlapping slots 94 to give the desired flexibility, axialforce and torque transmission.

FIG. 6 illustrates a flattened portion of exemplary tubular member 96,including fixation portion 98, steerable portion 100, and proximalneutral portion 102. Steerable portion 100 includes substantiallystraight slots 108 that are substantially perpendicular to thelongitudinal axis of tubular member 96, but each is offset relative tothe adjacent slot so that spine 106 has a sinuous shape extending alongthe length of steerable portion 100. Fixation portion 98 includes holes104 therethrough (four shown) to facilitate bonding. Proximal portion102 includes multiple overlapping slots 110 to give the desiredflexibility, axial force and torque transmission characteristics.

FIGS. 7A and 7B illustrate exemplary portions of flattened first andsecond tubular members 112 and 128. First tubular member 112 can be aninner tubular member and second tubular member 128 can be an outertubular member, or first tubular member 112 can be an outer tubularmember and second tubular member 128 can be an inner tubular member.Tubular members 112 and 128 can be assembled as part of a steerabledelivery device. That is, one of the first and second tubular memberscan be disposed within the other. First tubular member 112 includesfixation portion 114, steerable portion 116, and proximal neutralportion 118. Fixation portion 114 includes holes 120. Steerable portion116 has slots 124 formed therein to define spine 122. Spine 122 has agenerally sinuous shape. Proximal portion 118 includes a plurality ofoverlapping slots 126. Second tubular member 128 includes fixationportion 130, steerable portion 132, and proximal neutral portion 134.Fixation portion 130 includes holes 136. Steerable portion 132 has slots140 formed therein to define spine 138. Spine 138 has a generallysinuous shape. Proximal portion 134 includes a plurality of overlappingslots 142.

In FIGS. 7A and 7B, the slots in each of tubular members 112 and 128 areoffset relative to the adjacent slot, interrupted, and have a generalhelical configuration. Spines 122 and 138 have generally sinuousconfigurations. The slots in the tubular members are at the same anglerelative to the longitudinal axis of the tubular member, but are formedin opposite helical patterns. An advantage of having inner and outertubular members with slots that are not in alignment (as opposed toinner and outer tubular members that have slots perpendicular to thelongitudinal axis of the tubular member) is that the slots are lesslikely to get caught up on one another as the steerable portion issteered. The angled slots shown in FIGS. 7A and 7B also provide for anincreased torque response based on a torque applied at the proximal endof the device.

FIG. 8 illustrates a portion of an exemplary steerable delivery device.Steerable device 150 includes outer tubular member 152, inner tubularmember 154, and intermediate tubular member 156. A portion of outertubular member 152 and intermediate member 156 are cut away to showinner tubular member 154. Intermediate tubular member 156 can be aflexible polymeric tube. Inner and outer tubes 152 and 154 have slots160, 164 formed therein to define spines 158 and 162. The spines aresubstantially 180 degrees apart, as shown. The slots formed in therespective tubular members are at an angle relative to the longitudinalaxis of the steerable portion and are formed in opposite helicalpatterns.

FIG. 9 illustrates a portion of an exemplary steerable delivery device.Steerable device 166 includes outer tubular member 168 and inner tubularmember 170. Inner tubular member 170 can be a flexible polymeric tubularelement. Outer tubular member 168 has a plurality of slots 174 formedtherein to define spine 172. Inner tubular member 170 has nopreferential bending axis. Inner tubular member 170 could alternativelyhave a modified bending axis offset by having, for example, a stiffeningelement incorporated into the wall of inner tubular member 170approximately 180 degrees from spine 172. In some embodiments innertubular member 170 may incorporate wire braids and or axially-laid wireswhich reduce kinkability and increase axial stiffness as is common inbraided catheters or other similar known tubular medical devices.

FIG. 10 illustrates a portion of an exemplary steerable delivery device.Steerable delivery device 178 includes outer tubular member 180 andinner tubular member 182. Outer tubular member 180 can be, for example,a flexible polymeric tubular member. Inner tubular member 182 has aplurality of slots 186 formed therein to define spine 184, which issubstantially parallel to the longitudinal axis of the steerableportion. Outer tubular member 180 has no preferential bending axis.Alternatively, outer tubular member 180 can have a preferential bendingaxis. For example, a structural support element can be incorporated intothe wall of outer tubular member 180 approximately 180 degrees fromspine 184. Outer tubular member 180 can be substantially the same asinner tubular element 170 in FIG. 9, but for any lubricity enhancingfeature. In some embodiments inner tubular member 170 may incorporatewire braids and or axially laid wires which reduce kinkability andincrease axial stiffness as is common in braided catheter or othersimilar known tubular medical device.

In an alternative embodiment, the device includes inner and outerslotted tubes, and additionally includes an outermost tubular membersimilar to 180 shown in FIG. 10. The outermost tubular member can be,for example without limitation, a polymeric tubular member.

FIG. 11A illustrates a portion of an exemplary embodiment of a firsttubular member that can be included in a steerable delivery device.Tubular member 190 is a tubular member formed from a ribbon wire.Tubular member 190 has spine 192 formed by coiling a ribbon shaped withinterlocking elements 194 and 196, which together form an interlockingfeature along spine 192. Interlocking elements 194 and 196 may bepress-fit to interlock the two. The interlocking elements can be encasedwith a tubular member, such as a polymer tubular member, to secure themin place. The interlocking elements can also, or alternatively, have apolymer tubular member disposed therein to help secure them in place. Inaddition to the interlocking features, the ribbon wire has sections ofdecreased width 198 which once wound into a tubular structure create thesteerable portion for flexibility. A second tubular member of thesteerable delivery device can be created in a similar manner to thetubular member in FIG. 11A. FIG. 11B illustrates an embodiment of theribbon with interlocking elements 196 and decreased width regions 200between elements 196. The angle of interlocking elements 196 relative tothe longitudinal axis of the tubular element can be varied based on thepitch of the coil. Such a pattern can additionally be fabricated bylaser machining.

FIGS. 12A and 12B illustrate an exemplary embodiment of a tubularmember. Tubular member 210 comprises a tube 214 with grooves 212 formedtherein on the outer surface of tube 214. Grooves 212 do not extend allthe way through tube 214. Tubular member can be, for example, a stiffpolymeric tubular member. FIG. 12A shows a sectional view of a portionof tubular 210 showing the depth of grooves 212 in the steerableportion. FIG. 12B illustrates a flattened view of tubular member 210showing grooves 212 formed in tube 214. Grooves 212 define a singlesubstantially straight spine 216. Grooves 212 cut into tube 214 increaseflexibility of the steerable portion to allow the steerable portion tobe steered. Spine 216 provides for the application of compressive andtensile forces to steer the device. Because the cut does not go all theway through the wall of the tube, it inherently creates a fluid tightbarrier and a lubricious liner. In some embodiments tubular member 210can be an inner or outer tubular member of a steerable device, and theother of the inner and outer tubular elements can also include a tubularelement with grooves formed thereon. In some embodiments the steerabledevice can also have a polymeric sleeve to encapsulate the outer tube tocreate a smooth outer surface.

FIG. 13A illustrates a portion of an exemplary introducer sheathreinforcement member 220. Member 220 is formed by laser cutting atubular member to slots or gaps therein. A helical slot 222 definesinterlocking T-shaped patterns 224 formed in reinforcement member 220.The helical path is shown generally in helical path 226. Flexibilityslots 228 are formed in member 220 to provide flexibility to member 220.Member 220 also includes bonding slots 230 formed therein to allow forbonding to one or more components of the device. FIG. 13B illustratesmember 220 from FIG. 13A in a flattened pattern showing the interlockingT-shaped pattern along helical path 226, flexibility slots 228, andbonding slots 230. FIG. 13C shows a close-up of the section shown inFIG. 13B.

In some embodiments a guide catheter includes a relatively rigid metalor polymer reinforcement member (an example of which is shown in FIGS.13A-13C) layered between an inner and an outer flexible polymer tube.The rigid reinforcement member can be laser machined or otherwise cut ina pattern in order to enhance flexibility along the longitudinal axis ofthe tube, to allow some limited radial compliance, and to allow bondingof the inner and outer flexible polymers. The slot pattern can includean interlocking T-shaped pattern arranged helically around the tube forflexibility and radial compliance, a slot pattern where the slots aresubstantially perpendicular to the tube longitudinal axis, and arepatterned along the tube longitudinal axis to further enhanceflexibility and bonding of said layers.

FIG. 14 illustrates an exemplary embodiment of a guide system adapted toguide and deliver a therapeutic, diagnostic, interventional, or anyother type of medical device 260 intraluminally to a target locationwithin a body. Guide system 250 includes outer guide member 252 andsteerable delivery device 256, a portion of which is disposed withinouter guide member 250. Steerable delivery device 256 can be, forexample, any of the steerable delivery devices described herein. Outerguide member 252 has a preset bend 254 that can be formed by, forexample, heat setting. Steerable delivery device 256 includes steerableportion 258, which can be formed as, for example, any of the steerableportions described herein. For example, steerable delivery device caninclude outer and inner tubular members, wherein at least one of thetubular members is adapted to preferentially bend in a first direction.In the embodiment shown in FIG. 14, steerable portion 258 is comprisedof a single steerable tubular member steered into the configurationshown in FIG. 14 by actuating pull wire 264. Alternatively, steerabledelivery device 256 can be comprised of the embodiment described in FIG.2, and steered by relative axial movement of inner and outer tubularmembers, as described herein.

Alternatively, outer guide member 252 can be adapted to be bent usingoptional pull wire 262, shown in FIG. 14. In such an embodiment bend 254may or may not preset. Guide member 250 comprises a tubular memberincorporating a pattern of slots as described for steering portionsherein. When located in position pull wire 262 is tensioned and theaxial and torsional stiffness of bend 254 is thereby increased. Asteerable outer guide member 252 in its delivery configuration(non-bent) is generally loose and compliant, but is tensioned orcompressed to reconfigure it into a pre-set shape. Its stiffness in thebent configuration is a function of the amount of tension or compressionapplied and the particular slot pattern chosen.

Bend 254 in outer guide member 252 is compliant enough to bestraightened for delivery, for example advanced on a guide wire, butrigid enough to be able to guide steerable delivery device 256 aroundbend 254. Steerable delivery device 256 is steerable and transmitstorque.

The structural properties of the inner and outer tubular members of thesteerable delivery device will determine the manner in which theyrespond to force applied thereon. The structural properties of the innerand/or outer tubes will depend on the tubing material and the design, orcharacteristics, of the slots created in the tubular members (unless oneof the inner and outer tubular members does not have any slots therein).The design of the slot pattern is therefore a function of the requiredstructural properties of the tubular member. For example, structuralproperties of the tubular member that can be modified by changing thedesign of the slots or slot patterns include flexural stiffness, torquetransmission, steerability, radius of curvature, and allowable wallthickness of the steerable assembly.

FIG. 15 is a flattened view and illustrates a portion of an exemplarysteerable portion of a tubular member. Tubular member 290 can be aninner or an outer tubular member as described herein. Steerable portion290 is typically a laser-cut tubular member, but may in fact befabricated by any technique capable of creating the appropriate widthsof cuts required (e.g., water jet, wire EDM, etc.) wherein first cut, orslot, 292 is made, defined by first surface 294 and second surface 296.Slot 292 extends almost all the way around tubular member 290, anddefines spine 308. Slots 282 are thickest, along the tubularlongitudinal axis, along compression axis C which allows tubular memberto be compressed along compression axis C, which changes theconfiguration of tubular member 290. Tubular member 290 also includesinterlocking features 298 (only one of which is labeled), which includefirst interlocking element 300 and second interlocking element 302. Slot292 includes slot portion 304, which is defined by the first and secondinterlocking elements 300 and 302 and allows for movement between thetwo interlocking elements 300 and 302 in the axial direction. Tubularmember 290 also includes stress relief slots 306, which extend acrossspine 308 and provide stress relief for spine 308. Stress relief slots306 can be considered to be axially in-between slots 292. Slots 292 arenot connected with slots 306. Slots 306 are substantially thinner thanslots 292. As will be described in detail below, tubular member 290 isadapted to be compressed along compression axis C, which issubstantially 180 degree from spine 308.

FIGS. 16A and 16B illustrate a portion of tubular member 290 shown inFIG. 15. FIG. 16B illustrates tubular member 290 with slot 292, with agreatest thickness along compression axis C. Slot 292 includes slot 304,which is defined by interlocking elements 300 and 303. Slot 292 and slot304 allow for compression of tubular member 290, shown in FIG. 16A. Whena compressive force A is applied along compressive axis C surfaces 294and 296 are brought closer towards another, as are surfaces 300 and 302.Slots 292 and 304 therefore allow for axial compression of tubularmember 290, until surfaces 294 and 296 engage one another, or untilsurfaces 300 and 302 engage one another, whichever happens first. Slots292 and 304 can be designed such that the slots close at the same time.Once the surfaces engage, they behave substantially like a solid tubeand can no longer be compressed along the engagement points. In thisconfiguration, the first and second interlocking elements are adapted toprevent movement therebetween at least along a first axis, in thisembodiment along compression axis C. Upon a compressive force to tubularmember 290, tubular member will therefore be steered into theconfiguration shown in FIG. 16A.

Similarly, when a tensile force is applied to tubular member 290 shownin FIG. 16A, tubular member 290 will straighten to the configurationshown in FIG. 16B. Particularly, tubular member 290 will straightenuntil the interlocking features engage one another and prevent furthermovement. FIG. 16C illustrates the tubular member from FIGS. 16A and 16Band indicates points of load application including those illustrated inFIGS. 16B and 16C. Torsional force T indicates a torsional force actingon tubular member 290 upon the application of torque at a proximal endof the device. Tensile and compressive forces are listed as “a” or “b”depending on the behavior exhibited by the tubular member as describedbelow.

FIG. 17 is a graph illustrating Force v. Displacement behaviorassociated with the application of loads or displacements at variouspoints around tubular member 290 shown in FIGS. 15-16C. TheForce/Displacement behavior of tubular member 290 for loads applied inplanes passing through the longitudinal axis of the tubular member,ranges between the lines A and B in FIG. 17. Curve A illustrates thebehavior along a compliant axis on the surface of the tubular member andparallel to the longitudinal axis of the tubular member where the slotsare widest, while curve B illustrates the behavior where the slots arevery narrow. As the tubular member is bent about spine 308 in a fashionwhich closes slots 292, the forces required to bend the tubular memberare low and the Force/Displacement curve has a small slope. The tubularmember is compliant in this region. When the width of the slotsdecreases to zero the structure becomes much stiffer as indicated by thesecond much higher slope region of curve A. The amount of displacementassociated with closing the slots is essentially indicated by point Dwhere the slope of the Force/Displacement curve changes. Curve Aindicates the behavior expected from forces applied at a point alongcompressive axis C, illustrating that a large amount of axialdisplacement follows from minimal compressive force on tubular member290. Upon closing slots, the compressive axis becomes stiff (indicatedby the large increase in Force at point D in the curve). Curve B in thegraph indicates compression along the axis running through spine 308.Due to stress relief slots 306, a small amount of compressivedisplacement occurs before spine 308 stiffens and begins to actsubstantially like a solid tube, as indicated by point E in the graph.The structure will exhibit the behavior of curve B for tensional loadsapplied to the top of the structure on the compressive axis C as thegaps closed under this loading are very narrow. Curve B also representsthe behavior of the structure to torsional loads, as the gaps impactedmost by these loads are narrow.

FIG. 18 illustrates a flattened view of exemplary tubular member 320.Slot 330, or cut, formed therein has a spiral (also referred to hereinas helical) pattern and is uninterrupted. Tubular member 320 is shown inan as-cut compressed configuration, and is adapted to be expanded thegreatest amount along expansion axis EA upon the application of atensile force thereto. Tubular member 320 includes interlocking features332, which include surfaces 322 and 324, and surfaces 326 and 328. Slot330 includes the slot defined by surfaces 326 and 328, and by surfaces322 and 324. In this embodiment the slot, or gap, defined by surfaces326 and 328 is larger than the gap defined by surfaces 322 and 324. Thatis, the gap that is closer to expansion axis EA is larger than the gapthat is further from expansion axis EA. Tubular member 334 also includesspine 334, which is interrupted by small slots 336. As illustrated inFIG. 16C, tubular member 320, upon the application of axial loadsapplied thereto, will exhibit Force/Displacement curves as follows: acompressive force (downwards) applied at EA will exhibit curve B, whilea tensile load at EA (upwards) will exhibit curve A. A torsional loadwill exhibit curve B.

FIG. 19 is a flattened view and illustrates a portion of a tubularmember. Tubular member 270 can be an inner or an outer tubular member asdescribed herein. Steerable portion 270 is a laser-cut tubular memberwherein first cut, or slot, 274 is made to define spine 276. Cut 274 ismade almost all the way around tubular member 270. Cut 274 also definesinterlocking features 278 (only one of them is labeled), which arecomprised of a first interlocking element 280 and a second interlockingelement 282. Cut 274 includes cut 284, which creates the interlockingfeatures and allows for movement between the two interlocking elements.Tubular member 270 also includes stress relief 272, which extend acrossspine 276 and provide stress relief for spine 276. Stress relief slots272 can be considered to be axially in-between slots 274. Slots 274 arenot connected with slots 272. Tubular member 270 is adapted to beexpanded along expansion axis EA, and is adapted to be minimallycompressible upon the application of compressive forces thereto. Spine276 is substantially static. Upon the application of tensile forces totubular member 270 along expansion axis EA, tubular member 270 willdeflect from a straightened configuration into a bent configuration.

FIG. 20 illustrates an embodiment similar to that shown in FIG. 18 andonly differences in the structure between the two will be described. Allother features can be considered the same. Tubular member 350 includesinterlocking features including interlocking elements 354 and 356. Slot360 created in tubular member 350 includes the gap defined by surfacesof interlocking elements 354 and 356.

FIG. 21 illustrates a flattened portion of an exemplary tubular member380 including interrupted cuts 390 that define spine 382. Tubular member380 includes interlocking features 384, which include interlockingelements 386 and 388. Interlocking features 384 allow for expansionalong expansion axis EA upon the application of a tensile force thereto.Tubular member 380, like all tubular members described herein unlessspecifically stated otherwise, can be incorporated into a steerableportion as an inner or an outer tubular member.

FIG. 22 illustrates a flattened portion of an exemplary tubular member400. Interrupted slots 404 define spine 402, which has a spiral shape.Tubular member 400 does not have static axis.

FIG. 23 illustrates a flattened portion of an exemplary tubular member410. Tubular member 410 includes interrupted helical slots 418, whichdefine spines 412 and 414. Tubular member 410 has two spines, 180degrees around the periphery of the device from one other. The helicalcut pattern repeats itself every 180 degrees to define substantiallystraight spines. Tubular member 410 also includes a plurality ofinterlocking features 420 which provide torsional stiffness. The maximalexpansion/compression is at axis 416.

FIG. 24 illustrates a flattened portion of an exemplary tubular member430, which is similar to the embodiment in FIG. 23 but rather thanrepeating every 180 degrees, the cut pattern repeats every 360 degrees.Slots 434 have an interrupted helical design, and tubular member 430 hasa single spine 432. Feature 436 provides additional torsional stiffness.Tubular member 430 exhibits maximal expansion/compression along axis438.

FIG. 25 illustrates a flattened portion of an exemplary tubular member440. Tubular member 440 includes slots 448, which repeat every 190degrees to define spines 442 and 446. The slots have an interruptedhelical pattern, and create a relatively neutral pattern.

FIG. 26 illustrates a flattened portion of an exemplary tubular member450. Tubular member 450 has uninterrupted slot 456 formed therein, whichrepeats every 360 degrees. Tubular member 450 also includes interlockingfeatures 454 comprised of at least two interlocking elements asdescribed herein. In this embodiment, the interlocking elements havecomplimentary curved surfaces and are adapted to support rotation. Slot456 defines spines 452, while slot 456 allows compression and/orexpansion along axes A.

FIG. 27 illustrates an exemplary steerable delivery device includingsteerable portion 520. Steerable delivery device includes outer tubularmember 522, inner tubular member 524, and floating inner member 534.Inner tubular member 524 is disposed within and coaxial to outer tubularmember 522, and floating inner member 534 is disposed within and coaxialwith inner tubular member 524. Floating inner member 534 is axiallyfixed relative to inner tubular member 524 at a location proximal tosteerable portion 520. The device shown in FIG. 27 can also include aliner member disposed between the outer and inner tubular members.

FIG. 28 illustrates an exemplary steerable delivery system 600. System600 includes control device 602 that is adapted to steer steerableportion 610 of a steerable delivery device. The steerable deliverydevice includes outer tubular member 606 and inner tubular member 608disposed within outer tubular member 606. Control device 602 includeshousing 612 with a slot therein adapted to allow for movement ofactuator 604. Actuator 604 is coupled to inner tubular member 608, andis adapted to be moved axially, either distally D or proximally P tocontrol the axial movement of inner tubular member 608. Any othersuitable type of actuator can also be used including actuatorsincorporating mechanical advantage. Actuation of actuator 604 causesinner tubular member 608 to move axially relative to outer tubularmember, which causes steerable portion 610 to bend. The control deviceis therefore adapted to steer steerable portion 610 inside of a subject.System 600 also includes a floating liner member 616 and hemostaticvalve 614.

One aspect of the disclosure is a guide device that is adapted to bemaintained, or locked, in a specific configuration to provide access fora medical device or instrument to be passed therethrough, but may or maynot be steerable. In FIGS. 2A-2C, steerable portion 32 is adapted to besteered or deflected into any configuration between those shown in FIGS.2A and 2B. Steerable portion is adapted to be steered to, for example,navigate bends or turns within a bodily lumen. In that specificembodiment, compressive and/or tensile forces are applied to the innerand/or outer tubular members to steer the steerable portion. In someembodiments, once steerable portion 32 is steered into a curvedconfiguration, the forces applied thereto (e.g., compressive, tensile,torsional) can be released, and yet a medical device or instrument canbe passed through the tubular members. In some embodiments, however, thebent configuration of the steerable portion can be maintained bymaintaining the application of the forces thereto. For example, in FIGS.2A-2C, steerable portion 32 can be maintained, or locked, in the bentconfigurations shown by maintaining the application of the compressiveand/or tensile forces. By maintaining the application of the forces tothe steerable portion or locking the relative displacements of the innerand outer tubes, the inner and outer tubes are substantially axiallyfixed relative to one another along the length of the steerable portion.

In an exemplary method of use, multiple bend portions may beincorporated and adapted to have a locked configuration that closelymimics, or resembles, a portion of the subject's anatomy. The bendportion can be advanced through the subject (e.g., over a guide wire) toa desired location, and can then be actuated into a curvedconfiguration, such as by the application of compressive and/or tensileforces thereto. The curved configuration can be adapted to resemble thepath of the anatomical lumen in which the device is positioned.Application of the actuation force maintains, or stiffens, the bendportions in the desired curved configuration. A medical device orinstrument can then be advanced through the curved portion to a targetlocation within the subject.

The device shown in FIG. 14 can alternatively be configured to beoperated in this manner. For example, steerable delivery device 256 inFIG. 14 can be actuated to have a first bend or curved region 254 and asecond bend or curved region 258. The curves, or bends, form a generalS-shaped portion of the device. The delivery device 256 can bemaintained, or locked, in the general S-shape to guide a medical deviceor instrument therethrough. The S-shape of the delivery device 256 canbe used if it resembles a portion of the anatomy into which it isplaced, but any other type of preformed configuration can be used,depending on the anatomical requirements. In the alternative to FIG. 14,the delivery device can be actuated into the configuration shown by theapplication of compressive and/or tensile forces to inner and outertubular members, as is described herein.

FIGS. 29-34 show an alternative embodiment of a steerable deliverydevice. FIGS. 29-34 illustrate steerable delivery sheath 900 capable ofbending in one direction with torqueability and bend retentionenhancements. FIG. 34 is an enlarged view of a distal-most portion ofsheath 900. Sheath 900 includes inner tubular member 930 and outertubular member 920, respectively. Cross sections of sheath 900 arerepresented in FIGS. 30-33. Locations of cross sections are indicated assections A-A, B-B, C-C, and D-D as indicated in FIG. 29. Construction ofsheath 900 in proximal portion 913, shown in cross section D-D shown inFIG. 33, is similar to the proximal portion for sheath 810. Table 1describes component properties for an exemplary embodiment of the sheathshown in FIGS. 29-34. As in sheath 810, the distal-most portions of theinner and outer tubular members 930 and 920 are merged together, as isshown in section A-A in FIG. 30. In section A-A they are thuspermanently axially fixed. Inner tubular member 930 includes threediscrete components—inner layer 931, braided layer 932, and outer layer933. In this embodiment inner layer 931 is a lubricious liner, layer 932is a braided material embedded in PEBAX outer layer 933. Outer tubularmember 920 includes inner layer 921, intermediate layer 922, and outerlayer 923. In this embodiment, inner layer 921 is a lubricious liner,intermediate layer 922 is a braided material embedded in outer PEXAXlayer 923.

In contrast to sheath 810, however, inner sheath 930 incorporates anadditional stiffening element 945 that provides stiffness, only intension, along the axis falling on the plane within which the distal endof the sheath bends. The proximal end of stiffening element 945 isembedded in the outer polymer layer 933 of the inner tubular member 930at a location in a distal portion of the proximal portion 913 of theinner tubular member 930, as shown in FIG. 33. Stiffening element 945 isfree floating in the annular space 943 between inner tubular member 930and outer tubular member 920 throughout the remaining portion ofproximal portion 913, as well as in distal bendable portion 914 ofsheath 900 up to a point at the distal end of distal portion 914 wherethe distal portion of stiffening element 945 is embedded in outerpolymer layer 923, which is shown in section A-A in FIG. 30. Stiffeningelement 945 is located in the plane through which the distal end ofsheath 900 bends and is located on the inside radius of the bend. Insome embodiments stiffening element 945 is a multi-stranded Kevlar line.In some embodiments the proximal end of stiffening element is secured tothe outer layer of the inner tubular member at a location that is closerto the steerable portion of the device than a proximal end of the innertubular member.

Distal portion 914 is the steerable portion of sheath 900 and isconstructed as follows. In the proximal region of distal portion 914(section C-C), the braid in layer 922 is replaced by a tubular structurewith cutouts, and can be a metal tubular structure. The cutouts allowfor the controlled variation in the bending stiffness of the outertubular member in different planes which extend through the longitudinalaxis. The cutout pattern may additionally incorporate features toenhance torsional stiffness.

In this embodiment element 925 is a part of the spine of pattern cuttube 922 and 927 is an aperture passing through all layers of thedevice.

TABLE 1 1-way steerable sheath Proximal Central/Middle Distal Innersheath Liner 1 to 2 mil 1 to 2 mil 1 to 2 mil PTFE PTFE PTFE BraidedMaterial Diamond Diamond Diamond PEBAX (Durometer) 70 to 80 50 to 70 20to 40 Outer Sheath Liner 1 to 2 mil 1 to 2 mil 1 to 2 mil PTFE PTFE PTFEBraided Material Herring Herring None Cut Tube None None Patterned PEBAX(Durometer) 70 to 80 50 to 70 20 to 40

A representation of the performance of such a tube with cutouts isdepicted in FIG. 35 where curve 951 represents the stiffness incompression along axis on the periphery of the tube parallel to thelongitudinal axis of the cut tube. The stiffness is represented on apolar plot where r represents the stiffness and theta the angle aroundthe longitudinal axis pointing at the measurement axis. One embodimentof a cut-out pattern incorporating both controlled variation in bendingstiffness and features which enhance torsional stiffness is representedas a flat pattern in FIG. 36.

Bending in the steerable portion 914 of steerable sheath 900 occurs byaxially translating the inner and outer tubular members relative to eachother along the longitudinal axis. In some embodiments this isaccomplished by fixing the outer sheath 920 to a handle or externalcontroller incorporating an internal mechanism that is adapted totranslate inner tubular member 930. As inner tubular member 930 istranslated distally relative to outer sheath 920, compressive forces areapplied to outer sheath 920. These compressive forces cause distalportion 914 of sheath 900 to bend in the direction of its most compliantaxis, indicated by 929 in FIGS. 34, 35 and 36. As illustrated stiffeningelement 945 is adjacent to axis 929 and provides additional tensionalstiffness to inner sheath 930 on this axis while allowing the opposedaxis 928 to stretch. Sheath 900 in FIG. 34 additionally incorporates aradio opaque marker 927 at its distal end. 926 is a cut out in layer 922through which polymer can pass, as shown in FIG. 31. The section withthe square cutouts is completely embedded in polymer, hence all of thematerial is secured together at the distal end in FIG. 34 allows for thedelivery of fluid from within the sheath to outside the sheath when thedistal end of the sheath is plugged as might occur when the device isused to deliver a balloon which is inflated after delivery through thesheath and pulled back against the distal end.

In the embodiments shown in FIGS. 29-34, the inner and outer tubularmembers may be rotated relatively to one another, thereby causing thebent distal end of the sheath to rotate in a generally circular arc asshown in FIG. 37. This allows for more control of the distal tip by veryfinely torqueing just the distal end. This type of control minimizeswhipping to an even greater degree.

FIG. 38 illustrates an exemplary steerable device that can be controlledas described herein. The device includes an exemplary externalactuatable component incorporated into a handle at its proximal end. Thehandle includes a first actuator at its distal end that is adapted to beactuated (e.g., rotation) to deflect, or steer, the tip as describedherein. The handle also includes a second actuator at its proximal endthat is adapted to be actuated (e.g., rotation) for fine tune torqueadjustment as described in FIG. 37.

FIGS. 39-41 illustrate an exemplary external controller, in the form ofa handle, that is adapted to deploy and actuate the steerable devicesdescribed herein. The external controller is adapted, or can be adaptedto control other steerable devices not specifically described herein.FIGS. 39 and 40 illustrate the proximal portion of an exemplarysteerable sheath system 1000 that includes steerable sheath 1100, suchas those described above, and handle portion 1200 for actuatingsteerable sheath 1100. Handle portion 1200 includes sheath flexureadjustment knob 1210, grip 1220, guide wire port 1230, inner lumen purgeport 1240 leading into central lumen 1150. Flexure, or steering, of thesteerable sheath is facilitated by twisting control knob 1210 relativeto handle grip 1220. The amount of flexure of the sheath is related tothe amount of rotation of adjustment knob 1210. In some embodimentsthere will be a relatively linear correspondence between the degrees ofrotation of control knob 1210 and the angle of flexure for the sheathsteerable section. In such an embodiment each unit of incrementalrotation of the control knob 1210 substantially equals or “maps” into acorresponding and constant unit of incremental flexure for the sheathsteerable portion, independent of the starting flexure of the steerablesheath. In alternate embodiments there can be a nonlinearcorrespondence. For example, in an exemplary configuration when thesteerable section is at minimal flexure, control knob 1210 can imparttwice as much flexure as when it is at about 50% of its allowableflexure.

Other mappings are considered here although not described in detail.FIG. 40 illustrates a cross-sectional view of handle portion 1200 ofFIG. 39 at a midline plane. Situated at the proximal end is guide wirepass-through 1230 which sits proximal to guide wire seal 1250 leadinginto central lumen 1150.

Additional features comprising the control mechanism 1330 are alsoshown. Control knob 1210 sits over drive nut 1330 and is constrainedagainst rotation relative to the drive nut by drive nut feature 1380.Control knob 1210 and drive nut 1330 in turn are positionedconcentrically around drive screw 1310. Outer sheath interface tube 1340sits concentrically within the drive nut 1330.

Outer shaft 1110 is anchored to the outer sheath interface tube at 1140.Anchoring may be accomplished with adhesives, ultrasonic welding, heatstaking or other suitable means. Inner shaft 1120 is anchored at 1130 toinner sheath interface tube 1370 via any of the mechanisms described forthe outer sheath.

Handle housing 1220 feature 1320 passes through a proximal end of outersheath interface tube 1340 constraining it from both rotation and axialdisplacement. Pins 1320 additionally ride in the drive screw stabilizingslot feature 1350 of drive screw 1310 pictures in FIG. 41. FIG. 41depicts a portion of control mechanism 1300 with housing featuresremoved. As control knob 1210 is rotated, drive nut 1330 is constrainedto rotate with it via features 1380 and corresponding feature within thecontrol knob, not shown. Since drive screw 1310 is constrained againstrotation by the drive screw stabilizing pin 1320 riding in slot 1350,rotation of drive nut 1330 is translated into a linear motion for drivescrew 1310. Drive screw thread 1360 may comprise a constant pitch or avariable pitch. Since the inner shaft is anchored to the inner sheathinterface tube which in turn is constrained from moving axially relativeto screw 1310, this in turn will be translated into axial motion of theinner sheath relative to the outer sheath and result in flexure, orsteering, of the steerable portion of the device.

An exemplary aspect of the disclosure includes embodiments thatfacilitate the visualization of portions of the steerable sheath whenused in a navigation system, such as the St. Jude NavX Navigation &Visualization Technology, or other impedance-based methods associatedwith identifying relative positions of system components within a livingor deceased body.

When a steerable device includes one or more tubular members, as in theembodiments described above, the distal section of one or more of thetubular member can sometimes compress, or shorten, when it is actuatedto straighten the tip of the steerable device. For example, in theembodiments above which include an inner tubular member disposed withinan outer tubular member, the distal section of the inner tubular membermay sometime compress, or shorten, when it is pushed in relative to theouter tubular member to straighten the steerable portion from a bentconfiguration towards a straighter configuration. In some of theseembodiments, the proximal section of the inner tubular member has agreater durometer (e.g., 72D) than the steerable portion (e.g., 35D).The lower durometer allows the steerable portion to bend. Theshortening, when it occurs, is an inefficient use of the displacement ofthe inner tubular member that is necessary to deflect the steerabledevice.

FIGS. 42A-42G illustrate an exemplary embodiment that reduces oreliminates the shortening. In this embodiment, the region of the innertubular member disposed on the inside of the curve in the steerableportion and the distal tip has a higher durometer than the rest of theinner tubular member in the steerable portion and distal tip. FIGS.42B-42D show cross-sections through sections A-A, B-B, and C-C asindicated in FIG. 42A. Device 1650 includes inner tubular member 1652,outer tubular member 1654, and tensioning element 1660. Outer tubularmember 1654 has the same durometer along the length of the outer tubularmembers. In section C-C, the inner tubular member includes a firstportion 1658 with a first durometer. In sections B-B and A-A, the innertubular member includes first portion 1658 with the first durometer anda second portion 1656 with a second durometer lower than the firstdurometer. First portion 1658 makes up about ¼ of the inner tubularmember in cross section. First portion 1658 is radially withintensioning member 1660 that is used to transfer tension from theproximal section of the tubular member to the tip of the device. Thehigher durometer in the portion on the inside of the curve prevents theshortening of the inner tubular member when actuated. FIG. 42G showssection G-G of the distal section indicated in FIG. 42E. First portion1658 can be seen on the inside of the curve radially within tensioningelement 1660. In one specific embodiment first portion 1658 is 72DPEBAX, and second portion 1656 is 35D PEBAX. These numbers are exemplaryand are not intended to be limiting.

FIGS. 43A-43D illustrate an alternative embodiment in which device 1700includes inner tubular member 1702 and outer tubular member 1704. Innertubular member 1702 has first section 1708 with a first durometer and aplurality of second sections 1706 with a second durometer lower than thefirst durometer. In this embodiment, the steerable portion (section B-B)and distal tip (section A-A) of the inner tubular member include twohigher durometer sections 1708. In this embodiment neither of the higherdurometer sections 1708 is radially within tensioning member 1710, andas such neither of sections 1708 is on the inside of the curve. The twohigher durometer sections 1708 are substantially opposite each otheraround the circumference of the inner tubular member, and are each about90 degrees apart from tensioning element 1710.

The exemplary steerable devices described in FIGS. 44-46 are similar tothose shown in FIGS. 42A-G above. In particular, the inner tubularmember of the steerable devices in FIGS. 44-46 is similar to innertubular member 1652 described in reference to FIGS. 42A-G above.

FIGS. 44A-44C illustrate exemplary inner tubular member 4100. FIG. 44Ais a top view. FIG. 44B is a view rotated 90 degrees relative to theFIG. 44A view, and FIG. 44C is a view rotated 180 degrees relative tothe view in FIG. 44A (and 90 degrees relative to the view in FIG. 44B).

Inner tubular member 4100 includes steerable distal section 4114 and aproximal section 4102. Proximal section 4102 includes a proximal tubularelement 4116 with a first durometer. In the embodiment shown proximaltubular element 4116 has a durometer of 72D and is a Pebax/Vestamidmaterial. Steerable distal section 4114 includes tubular element 4104and spine 4106. Spine 4106 is similar to first portion 1658 from FIGS.42A-G herein. Tubular element 4104 has a lower durometer than proximaltubular element 4116. In this embodiment tubular element 4104 has adurometer of 35D, and is Pebax. Spine 4106 has optional proximal anddistal cuff portions that extend all the way around the device, and aspine section that extends between the two cuff portions that does notextend all the way around the device. In the spine section spine 4106makes up about ¼ of inner tubular member 4100, and tubular element 4104makes up about ¾ of the inner tubular member 4100. Inner tubular member4100 also includes tensioning member 4108 that is secured to the distalend 4110 of cuff portion and to the distal end 4112 of proximal section4102. Tensioning member 4108 is free floating in between the two pointsat which it is secured. Tensioning member 4108 is directly adjacent to,and in alignment with, the spine section of spine 4106 (as can be seenin FIG. 44C). In this embodiment tensioning member 4108 is a Kevlarline. Spine 4106 has a greater durometer than tubular element 4104, andin this embodiment is 72D Pebax.

As is described in more detail above, the lower durometer of tubularelement 4104 relative to proximal tubular element 4116 allows thesteerable distal section to bend. Spine 4106, however, due to its higherdurometer, reduces shortening in compression and stretching in tension,as can occur in the distal section when it is actuated. For example, thedistal section of the inner tubular member may sometimes compress, orshorten, when it is pushed in relative to the outer tubular member tostraighten the steerable portion from a bent configuration towards astraighter configuration. The durometers provided are not intended to belimiting but merely illustrative.

FIGS. 45A-45C illustrate exemplary outer tubular 4200 that is part ofthe delivery device and is disposed outside of and around inner tubularmember 4100. FIG. 45A is a top view. FIG. 45B is a view rotated 90degrees from the view in FIG. 45A, and FIG. 45C is a view rotated 180degrees from the view in FIG. 45A (and 90 degrees from the view in FIG.45B).

Outer tubular member 4200 includes a proximal section 4202 andsteerable, or articulating, distal section 4214. Proximal section 4202has a proximal tubular element 4204 with a first durometer. In thisembodiment proximal tubular element 4204 is a 72D Pebax/Vestamidmaterial. Distal articulating section 4214 includes spine 4206, which isstructurally the same as the spine in FIGS. 44A-44C. Spine 4206 includesdistal and proximal cuffs and a spine section extending between the twooptional cuff portions. In this embodiment spine 4206 is 72D Pebax.Articulating section 4214 also includes first section 4208, secondsection 4210, and third section 4212, all of which have differentdurometers. In this embodiment the durometers decrease towards thedistal end of the device. In this embodiment first section 4208 is 55DPebax, second section 4210 is 40D Pebax, and third section 4212 is 35DPebax. The multiple sections of different durometer materials (three inthis embodiment) in the outer tubular member are arranged so that, asthe steerable portion is steered, the radius of curvature changes alongthe length of the steerable portion. In this embodiment, the radius ofcurvature of the steerable portion decreases along the length of thesteerable portion, and thus is less in the distal region than in moreproximal sections. The steerable portion has a tighter curvature in thedistal region than in the proximal region. The configuration of thesteerable portion can be thought of as a spiral in this embodiment. Incontrast, in embodiments in which a single durometer material extendsthe length of the steerable portion (except for the spine), the radiusof curvature of the steerable portion is substantially the same alongthe length of the steerable portion (i.e., regardless of the locationalong the length of the steerable portion). In the single durometerdesign the radius of curvature does decrease in response to continuedexternal actuation, but the radius of curvature remains substantiallythe same along the length of the steerable portion. The curve thusbecomes tighter, but it has a substantially constant radius of curvaturealong the steerable portion. The materials and the arrangement of thematerials in the steerable portion can thus be selected depending on thedesired application of the device. For example, different degrees ofdesired bending, or steering, may differ depending on the intended useof the device, including any intended target location within the body.

Proximal tubular element 4204 has a greater durometer than all threesections 4208, 4210, and 4212. The distal articulating section 4214 alsoincludes distal tip 4216. In this embodiment distal tip 4216 is thelowest durometer material, and in this embodiment is 20D Pebax.

The embodiments herein with the outer spine and the multiple durometersteerable sections provides for advantages in bidirectional use. Forexample, less force is required to bend the multiple durometerarrangement, hence there is less foreshortening or conversely lessstretching when the element is used in tension. This advantage wouldalso hold true for unidirectional steering.

As is described in more detail in the assembly shown in FIGS. 46A-46C,the spines in the inner and outer tubular members are offset 4180degrees from one another. Tensioning member 4108 is therefore alsooffset 180 degrees from the outer spine.

FIGS. 46A-46E illustrate views of assembly 4300 including the inner andouter tubular members 4100 and 4200, respectively, from FIGS. 44 and 45.As can be seen in FIGS. 46A and 46E, tensioning member 4108 is offset180 degrees from outer spine 4206. The inner and outer spines are alsooffset by 180 degrees.

The assembly 4300 can be used as is described in the applicationsincorporated by reference herein. For example, the inner and outertubular members can be axially moved relative to one another to steerthe distal steerable section. When a spine from one tubular member isput in tension, the other spine is put in compression. The dual spineembodiment reduces shortening in one tubular member in compression andstretching in the other tubular member in tension.

In some embodiments the inner or outer tubular members are formed bypositioning the different materials on a mandrel, placing shrink wrapover the different materials, and increasing the temperature, whichcauses the material to melt together, forming the inner or outer tubularmembers. The optional cuffs described above can be helpful in securingone or more components together during the manufacturing process.

Any of the inner and outer tubular members described above that compriseone or more slots or spines can be made of an elastomeric or polymericmaterial. For example, the tubular members shown in FIG. 2, 3, or 4 withslots and spines therein can be made from Pebax or other polymericmaterials.

The embodiment in FIGS. 47-49 describes alternative designs for innerand outer shafts described herein. The assembly of the inner and outertubular member described in FIGS. 47-49 can be actuated and thus steeredin the same or similar manner as is described above. For example, thetubular members in the example in FIGS. 47-49 are axially fixed relativeto one another distal to a steerable portion, and the steerable portioncan be steered by actuating the inner or outer tubular member relativeto the other tubular member via actuation of an external device.Actuating the external device (e.g., a handle) causes the tubularmembers to be axially moved relative to one another proximal to thesteerable portion, which causes their relative axial movement in thesteerable portion, which thereby causes the steerable portion to besteered. The amount of relative movement between the tubular membersdecreases as the distance from the axial fixation location decreases.Due to the axial fixation, when one tubular member is put in tension,the other is under compression. For example, if the inner shaft is movedproximally relative to the outer shaft via actuation of the externalcontrol (and the proximal end of the outer shaft is not movedproximally), the inner shaft is put in tension. Because the shafts areaxially fixed and the outer shaft does not move proximally, the outershaft will be under compression. In alternative embodiments, details ofthe inner and outer tubular members disclosed above may be incorporatedinto the tubular members described in the embodiment in FIGS. 47-49,unless this disclosure specifically indicates to the contrary.

FIGS. 47A-47I illustrate details of an exemplary inner tubular member,which may also be referred to herein as an inner shaft (or member)subassembly. FIGS. 48A-48E illustrate details of an exemplary outertubular member, which may be referred herein as in outer shaft (ormember) subassembly. FIGS. 49A-49D illustrate details of the steerabledevice assembly comprising the inner and outer tubular members fromFIGS. 47A-47I and FIGS. 48A-48E, respectively. Additionally, theassembly in FIGS. 49A-49D illustrates a soft tip at the distal end,which can be added after the inner and outer tubular members areassembled.

FIGS. 47A and 47B illustrate side views of the steerable portion of anexemplary inner tubular member, with select portions cut away to reviewadditional detail. FIG. 47B is a side view that is 90 degrees around thetubular member relative to the side view in FIG. 47A. “Distal” is to theleft in the figure, and “proximal” is to the right in the figure. Thesteerable portion of the inner tubular member includes three sections ofmaterial that are each coupled with at least one adjacent section at aseam that is not parallel to and not perpendicular to the longitudinalaxis of the tubular member, and can be an angled seam. As shown in FIGS.47A and 47B, the steerable portion includes, in a proximal-to-distaldirection (right-to-left in FIGS. 47A and 47B), three differentsections, the durometer of the sections decreasing in theproximal-to-distal direction. For example, as shown in FIG. 47A, thesteerable portion includes section 473 (e.g., 72D Pebax), intermediatesection 472 (e.g., 55D Pebax), and proximal section 471 (e.g., 35DPebax). These durometers are merely exemplary and the other durometerscan be used. In some embodiments the durometers decrease in theproximal-to-distal direction, in others the central durometer may be thegreatest. The joint, or seam, between section 473 and 472 is notparallel to and not perpendicular to the longitudinal axis of the innershaft, and in some embodiments it is an angled seam. The joint betweensections 472 and 471 is also not parallel to and not perpendicular tothe longitudinal axis of the inner shaft, and in some embodiments is anangled seam. The joint may, however, not form a straight line betweenadjacent sections and still be considered to be non-parallel andnon-perpendicular to the longitudinal axis. In this embodiment thejoints are non-parallel and non-perpendicular to the longitudinal axisover substantially the entire joint. “Substantially the entire joint” inthis context includes joints that have end sections that areperpendicular to the longitudinal axis. “Substantially” in this contextrefers to joints wherein most of the joint is non-parallel andnon-perpendicular to the longitudinal axis, such as at least eightypercent of its length.

In this embodiment, the varying durometers in the three sections of theinner shaft have similar functionality to those described above in thecontext of FIGS. 45A-45C. The multiple sections of different durometermaterials (three in this embodiment) in the inner tubular member arearranged so that, as the steerable portion is steered, the radius ofcurvature changes along the length of the steerable portion. In thisembodiment, the radius of curvature of the steerable portion decreasesalong the length of the steerable portion, and thus is less in thedistal region than in more proximal sections. The steerable portion hasa tighter curvature in the distal region than in the proximal region.The configuration of the steerable portion can be thought of as a spiralin this embodiment. In contrast, in embodiments in which a singledurometer material extends the length of the steerable portion (exceptfor the spine), the radius of curvature of the steerable portion issubstantially the same along the length of the steerable portion (i.e.,regardless of the location along the length of the steerable portion).In the single durometer design the radius of curvature does decrease inresponse to continued external actuation, but the radius of curvatureremains substantially the same along the length of the steerableportion. The curve thus becomes tighter as it is steered, but it has asubstantially constant radius of curvature along the steerable portion.The materials and the arrangement of the materials in the steerableportion can thus be selected depending on the desired application of thedevice. For example, different degrees of desired bending, or steering,may differ depending on the intended use of the device, including anyintended target location within the body.

In the embodiment in FIGS. 42A-42G above, the average durometer in crosssections (perpendicular to the longitudinal axis of the shaft)throughout the inner shaft in the steerable portion remains constant. Inan effort to allows for tighter bending curves in the distal directionin the steerable portion during bending, at least one of the shafts inthe steerable portion can have an average durometer, in cross sectionsthrough the steerable portion, that varies along its length (i.e., isnot constant along its length). The varying average durometer can beincrementally (i.e., step-wise) varying (e.g., FIG. 45), or it can becontinuously varying (e.g., FIG. 47, via the non-parallel andnon-perpendicular seams). Any configuration of the seams can be chosento control the variance in the average durometer in the cross sections.

In other embodiments the outer shaft has a non-constant (i.e., varying)average durometer in cross section along its length. In some embodimentsboth of the shafts have varying average durometers in cross sectionalong their lengths.

In any of the embodiments, in either shaft, there can alternatively bemore than or fewer than three sections with different durometers in thesteerable portion.

In this embodiment the bending plane of the inner shaft is, in FIG. 47B,the plane of the page. The bending plane in this embodiment (and othersherein) is a plane that includes the spine, the longitudinal axis, andpreferential bending axis. The spine extends through the top of theshaft in FIG. 47B (although the spine itself in some embodiments is notnecessarily a linear “axis.” For example, a spine can have a midlineparallel to the longitudinal axis of the shaft that is an “axis”). Thepreferential bending axis is in the plane of the page and extendsthrough the bottom of the shaft in FIG. 47B. When put under compressionthe shaft will bend downward in the page in the bending plane. Whenbent, the spine, the longitudinal axis, and the preferential bendingaxis remain in the bending plane. With respect to the seam betweensections 473 and 472, the distal-most location of section 473 is in thespine, in the bending plane. The proximal-most location of section 472is along the preferential bending axis. Thus, the distal-most locationof the higher durometer material is along the spine, and theproximal-most location of the relatively lower durometer material isalong the preferential bending axis. As discussed above, the averagedurometer of the shaft, in cross section perpendicular to thelongitudinal axis, continuously varies from the proximal-most locationof section 472 and the distal-most location of section 473.

In this embodiment the distal-most location of the seam between sections473 and 472 is along the spine, and the proximal-most location of theseam is in the preferential bending axis.

The inner member includes a proximal portion 474 that is proximal to thesteerable portion. Proximal portion 474 is generally stiffer than thesteerable portion. In some embodiments proximal portion 474 is apolyamide, such as nylon or Vestamid. FIG. 47E shows cross section F-F(from FIG. 47A) through proximal portion 474.

FIG. 47C shows cross section G-G within the steerable portion from FIG.47A. The innermost layer is liner 476, which can be a lubricious linersuch as PTFE. Section G-G also shows a portion of support member 475 (inthis embodiment is a helical coil) embedded in the inner member. Supportmember 475 can be a stainless steel wire, and in section G-G is embeddedin distal section 471, which in this embodiment comprises 35D Pebax.Also embedded in distal section 471 is reinforcing member 477, which canbe, for example, a Kevlar line. The length of reinforcing member 471 andcoil 475 are shown in FIG. 47B.

FIGS. 47G-47I, respectively, show side views of distal section 471,intermediate section 472, and proximal section 473 before they areassembled.

FIG. 47F shows section J-J of the distal end of the device from FIG.47A. The ends of coil 475 are embedded in a thin polyamide such asVestamid, and the distal of the two is labeled 478 in FIG. 47E.Reinforcing member 477 can also be seen, the distal end of which isproximal to the distal end of the device. Inner liner 476 extends allthe way to the distal end of the device.

As shown in FIGS. 47G-47I, and as described above in the context ofFIGS. 47A and 47B, adjacent sections in the steerable portion meet at ajoint that is not parallel with and not perpendicular to thelongitudinal axis of the shaft, which in some embodiments can be veryslightly radially overlapped. In some embodiments it can be an angledjoint. The slight overlap can help diminish flaws associated with thekitting of the two materials. In embodiments in which the joints areangled, exemplary angles for the seams are shown in FIGS. 47G-47I, butthese are merely exemplary. One difference between the inner tubularmember shown in FIGS. 47A-47I and the inner members in the embodimentsabove is that reinforcing member 477, which can be a Kevlar material, iscompletely embedded in the inner tubular member, as opposed to beingfree-floating at certain points along its length or embedded in theouter surface of the outer member. A reinforcing member can also bewoven through a support member, such as a braided material. Thereinforcing member and the support member would then be embedded in theinner member. In this embodiment the reinforcing member is linearlyaligned with the spine of the shaft. A reinforcing member can thus bewoven through a braided material, extending in a generally lineardirection, and still be considered “linearly aligned” with a spine inthis context.

FIGS. 48A-48D illustrate an exemplary outer tubular member. FIGS. 48Aand 48B are the same relative views of the outer tubular member as arethe views from FIGS. 47A and 47B of the inner tubular member. The outermember includes a proximal portion 481 that is disposed proximal tosteerable portion 501. In an exemplary embodiment proximal portion 481can be a 72D Pebax material. Along steerable portion 501, the outertubular member includes sections of material that have differentdurometer. In this embodiment steerable portion 501 includes firstsection 487 with a high durometer than a second section 488. Firstsection 487 acts as a spine along steerable portion 501. In a merelyexemplary embodiment first section 487 can be a 72D Pebax material andsecond section 488 can be a 35D Pebax material. First section 487extends less than 180 degrees around the outer shaft, and second section488 extends more than 180 degrees around the outer shaft. The jointsbetween the two materials are parallel to the longitudinal axis (as thatterm is used in the art) of the outer shaft. In other embodiments,however, the joints between sections 487 and 488 can be non-parallel tothe longitudinal axis of the outer tubular member, and may also benon-perpendicular to the longitudinal axis of the outer tubular member.For example, the joint between sections 487 and 488 can include anangled joint.

FIG. 48C shows section A-A shown in FIG. 48A. The outer shaft includesan inner liner 484, which can be a lubricious liner such as PTFE.Supporting member 489, in this embodiment in the form of a braidedmaterial, is disposed around liner 484. The polymeric outer shaftincludes lower durometer section 488 and higher durometer section 487.As can be seen, the supporting member 489 is embedded in the polymerictubular member.

FIG. 48D illustrates section C-C of outer shaft shown in FIG. 48A(distal end towards the left in the figure). Immediately distal to thesection that includes first and second sections 487 and 488 is a sectionof material with higher stiffness than steerable section 501. In someembodiments section 485 can be a 72D Pebax material. Supporting member489 extends into section 485. Liner 484 also extends into section 485.Distal to section 485 is a tip section of outer shaft, which includes anouter layer 482 and an inner layer 486. Outer layer 482 is stiffer thaninner layer 486. As an example outer layer 482 can be a 72D Pebax, andinner layer 486 can be a 35D Pebax. The distal tip also include markerband 483, which is radially within outer layer 482 and radially outwardrelative to inner layer 486. The distal tip also includes a braidedmaterial captured, or retained, by marker band 483. Marker band 483 maybe formed from a radiopaque material such that the distal tip is visibleunder fluoroscopy. For example, marker band 483 may be formed from aradiopaque alloy, e.g., a platinum-iridium alloy.

FIGS. 49A-49D illustrate views of an exemplary steerable device thatincludes outer shaft 491 (from FIGS. 48A-48D) affixed to inner shaft 492(from FIGS. 47A-47I). The assembled steerable device also includes asoft tip 493 at the distal end that is affixed to the inner and outershafts after they are affixed to one another.

Components from FIGS. 47A-47I and FIGS. 48A-48D are again labeled inFIGS. 49A-49D. As can be seen most clearly in FIG. 49C, reinforcingmember 477 (e.g., a Kevlar line) of the inner shaft 492 is 180 degreesopposite from the midpoint of higher durometer section 487 (measurearound the perimeter of device orthogonal to the longitudinal axis) inthe outer shaft 491.

FIG. 49D shows section E-E of the device from FIG. 49A. There is a space505 between inner shaft 492 and outer shaft 491 in the steerableportion. As can be seen in FIG. 49D, inner shaft 492 and outer shaft 491are affixed to one another at the interface between section 471 of theinner shaft and inner layer 486 of the outer shaft (see inner layer 486in FIG. 48D). As can be seen in FIG. 49D, inner shaft 492 extendsfurther distally than outer shaft 491. The portion of inner shaft 492that extends further distally than outer shaft 491 includes section 471and inner liner 476. Soft tip 493 is disposed radially over the distalend of inner shaft 492, and is also axially interfaced with the distalend of outer shaft 491, as shown in FIG. 49D. The polymeric componentsare affixed to one another using known techniques. After soft tip 493 isaffixed, vent holes 510 are made in the assembly, which are aligned withthe reinforcing member 477 of inner shaft 492 and the spine of outershaft 491. The steerable device can be assembled to any of the handlesherein and can be actuated to steer the steerable portion in the mannersdescribed herein.

FIGS. 50A and 50B illustrate side views of a distal region of analternative inner tubular member 550, with the views in FIGS. 50A and50B 90 degrees relative to one another. Inner tubular member 550 can beused in combination with any of the outer tubular members herein. Inthis exemplary embodiment, steerable portion 553 includes first segment551 and second segment 552 interfacing at seam 558. Steerable portion553 is similar to the steerable portion in the embodiment in FIGS. 47Aand 47B, but in steerable portion 553 there are only two segments, 551and 552, that interface at a seam.

FIG. 50B illustrates that seam 558 comprises first and second seams 559and 560, which meat at seam distal-most location 563 and seamproximal-most location 562.

In this exemplary embodiment, seam 558 is angled along its entirelength, shown as length “L” in FIG. 50A. “Angled,” when used in thismanner, describes a seam that is not parallel with and not perpendicularto a longitudinal axis of the inner tubular member, which may be thesame as a longitudinal axis of a steerable medical device of which theinner tubular member is a part. The seam may also be angled alongsubstantially its entire length, such as at least 85% of its length. Forexample, the distal and/or the proximal-most locations of the seam mayinclude short straight sections that are perpendicular to thelongitudinal axis of the inner tubular member, and the seam can still beangled along substantially its entire length.

The angled seam 558 may also be described in terms of a comparison ofcross-sectional areas of the inner tubular member in the longitudinaldirection. For example, cross-sectional areas taken at differentlocations between distal-most point 563 and proximal-most point 562 ofthe steerable portion may include C-shaped segments having differentmaterial durometer that mesh to create a circular cross-section. By wayof example, a first cross-section taken several millimeters proximalfrom the distal-most point 563 may include a first C-shaped segmenthaving a higher durometer and having a smaller arc length, and a secondC-shaped segment having a lower durometer and having a larger arclength. By contrast, a second cross-section taken several millimetersdistal from the proximal-most point 562 may include a first C-shapedsegment having a higher durometer and having a larger arc length, and asecond C-shaped segment having a lower durometer and having a smallerarc length. In the case of seam 558 angled linearly and at a continuousangle between the distal-most point 563 and the proximal-most point 562,a third cross-section taken at a medial location between the distal-mostand proximal-most points may having a first C-shaped segment having ahigher durometer and a second C-shaped segment having a lower durometer,and the first and second C-shaped segments may have a same arc-length,i.e., may be semi-circular.

Seam 558 may include an angle relative to the longitudinal axis thatvaries over its length. For example, a seam that is angled alongsubstantially its entire length can still include one or more relativelyshort perpendicular or parallel seam sections along its length. That is,seam 558 may include discrete steps, each of which includes aperpendicular and a parallel segment relative to the longitudinal axis.Thus, the stepped profile of the angled seam 558 may progress around asurface of steerable portion 553 at an angle, even though one or moresegments of the seam are not directed at an angle.

Seam 558 may include other profiles that progress around the surface ofsteerable portion 553 at an angle. For example, the seam profile may becontinuous (as opposed to a discrete profile of a stepped seam profile),but the angle of the seam may vary. In an embodiment, thevariably-angled seam profile may include a wavy profile beginning at adistal-most location 563 and progressing around the surface of steerableportion in a wavy manner to a more proximal location that iscircumferentially offset relative to distal-most location 563.

While inner tubular member 550 includes a seam that is angled along itsentire length, inner tubular 550 is also an example of a tubular memberwith a seam, at least a portion of the seam being angled along itslength.

First segment 551 (which can also be considered a distal segment) has adurometer less than the durometer of second segment 552 (which can alsobe considered a proximal segment). In some embodiments, first segment551 has a durometer of 20D-55D, such as 25D-45D, and in a particularembodiment can be about 35D. In some embodiments second segment has adurometer of 55D-85D, such as 65D-85D, and in a particular embodiment isabout 72D.

In some embodiments the inner tubular member includes a segment oftubular material 554 proximal to the steerable portion, and segment oftubular material 555 proximal to segment 554. In some exemplaryembodiments section 554 can be a polyamide such as Vestamid®. In someembodiments segment 555 has a durometer between 55D-85D, such as65D-85D, such as about 72D. In other embodiments the inner tubularmember excludes section 555, and thus section 554 (e.g., a Vestamidmaterial) extends all the way to a handle assembly.

In some embodiments the difference in durometers between the first andsecond segments is at least 10D, at least 15D, at least 20D, at least25D, at least 30D, or even at least 35D. The one or more angled portionsof seam 558 create one or more transitioning portions of the innertubular member with a varying durometer along the angled seam.

The length of seam L as a percentage of the length of steerable portion“S” of inner tubular member 550 is, in this embodiment, relatively high.In this embodiment the length L is at least 80% of length S, but in someembodiment it can be at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%,90%, or 95%. An exemplary advantage of angled seam 558, and its relativelength, is that it can provide a more consistent, or smooth, curvatureto the steerable portion of the steerable medical device duringsteering. The angled seam creates a continuously changing stiffnessalong the length of the angled seam, due to the different durometers ofthe two materials. For example, a stiffness of inner tubular member 550may decrease, in a stepped or continuous manner, in a distal directionfrom proximal-most location 562 to distal-most location 563. Somealternative designs may have steerable portions that have a tendency toform “joints” along the steerable section during steering (i.e., a lesssmooth curvature), and the exemplary angled seam 558 can help reduce thelikelihood of a “jointed” steerable section, if desired.

In some embodiments the length of the seam L can be between 1 cm and 8cm, such as between 2 cm and 7 cm, or between 3 cm and 6 cm.

In some embodiments the length of the steerable portion S is from 3 cmto 9 cm, such as from 3 cm to 8 cm, or 4 cm to 7 cm, such as, withoutlimitation, 4.5 cm, 4.6 cm, 4.7 cm, 4.8 cm, 4.9 cm, 5.0 cm, 5.1 cm, 5.2cm, 5.3 cm, 5.4 cm, 5.5 cm, 5.6 cm, 5.7 cm, 5.8 cm, 5.9 cm, 6.0 cm, 6.1cm, 6.2 cm, 6.3 cm, or 6.4 cm.

In some embodiments the steerable medical device includes inner tubularmember 550 and, for example without limitation, the outer tubular memberin FIGS. 48A-D. The lengths of the steerable portions of both the innerand outer tubular members are generally the same, such as any of theexemplary lengths herein. Inner tubular member 550 can be incorporatedinto the steerable medical device such that the steerable portion issteered upon actuation of an external actuator, examples of which aredescribed herein. For example, in some embodiments the outer tubularmember is axially fixed with respect to an external handle, and theinner tubular member is operatively coupled with the external actuatoron the external handle such that actuation of the actuator causesrelative axial movement (e.g., proximal movement) of the inner tubularmember. A proximal force on the inner tubular member puts the innertubular member in tension, and because the inner and outer tubularmembers are axially fixed distal to the steerable portion, the outertubular member is put into compression, thereby steering the steerableportion.

Compression of the outer tubular member and tensioning of the innertubular member, or vice versa, may create length changes of differingamounts on opposing sides of the respective tubular members. Taking theinner tubular member as an example, tensioning of the inner tubularmember may stretch the side of the steerable portion having the lowerdurometer material more than the side of the steerable portion havingthe higher durometer material having the higher durometer material. Thedifference in material strain may translate into a radius of curvatureof the tubular member. A similar phenomenon may occur in the outertubular member under compression, in which the lower durometer materialis compressed more than the higher durometer material. In either case,it is noted that a radius of curvature is achieved through differentstrain rates of material along the solid walls, i.e., non-slotted, sidesof the tubular members. More particularly, the steerable portion may becurved and steered using tubular members that do not include slots,holes, or discontinuities in the walls of the tubular members over thesteerable portion. In alternative embodiments, one or both of the innerand outer tubular members may include a steerable portion that does notinclude a solid tube of polymeric material. For example, one or both ofthe inner and outer tubular members may have, in the steerable portion,one or more discontinuities in the polymeric member. Discontinuitiescould be in the form of, for example, one or more holes of anyconfiguration, or one or more slots of any configuration, and can extendalong any desired length of the steerable portion. One exemplaryfunction of such a discontinuity could be to act as a strain relief inone or more portions of the one or both tubular members. An exemplarymethod of creating a discontinuity could be to create one or more, forexample, holes in the polymeric material after the tubular member hasbeen formed.

The lengths of the steerable portion of the medical device, as well asthe configuration and properties of the different segments of materialin the steerable portion, will, generally, influence the configurationthat the steerable portion will assume when steered. The configurationincludes the tightness of the curve of the steerable portion after ithas been steered, or bent, to the fullest extent. The lengths of thesteerable section S set forth immediately above can allow the steerableportion to achieve a curve diameter 571 of 2.0 cm-3.5 cm, the dimensionof which is illustrated in FIG. 51B for an example steerable medicaldevice. Curve diameter 571 may also be expressed in terms of a radius.For example, a reach length 570 may be a radius of curvature of thesteerable portion when the steerable portion does not bend over 180degrees or more. Exemplary reach lengths 570 shown in FIG. 51A, which isthe dimension when the steerable portion is bent at 90 degrees, can be,for example without limitation, 2.7 cm-4.7 cm.

The proximal end of steerable portion 553 does not include an angledseam, and includes only second segment of material 552. Similarly, thedistal end of steerable portion 553 does not include an angled seam, andincludes only first segment of material 551, as can be seen in FIG. 50B.In an embodiment, however, one or more of the distal end of steerableportion 553 or the proximal end of steerable portion 553 may becoincident with distal section 556 or proximal section 554. That is, avertex of seam 558, i.e., a point whether seam portions 559 and 560meet, may coincide with a distal or proximal end of the steerableportion.

In some embodiments the segments 551 and 552 have the same length. Thelength of segments 551 and 552 will influence the location of the distalmost and proximal most location of the seam.

First and second segments 551 and 552 have the same configuration, butthey are offset by 180 degrees and face opposite directions. The firstand second segments need not, however, have the same configurations.

FIG. 50B illustrates seam portions 559 and 560 forming acute angles(only distal angle 561 labeled) at both ends of seam 558. The length ofthe seam can influence the angle formed by the two seam portions 559 and560. An “angle” as used in this context does not require two straightlines defining what is generally referred to as an angle. The generalconfiguration of seam portions 559 and 560 can form an acute angletherebetween even if seam portions 559 and 560 are not perfectlystraight lines in the side view (e.g., even if there is a slightcurvature to one or both of them). Furthermore, seam portions 559 and560 may meet at a vertex as described above, or alternatively, mayterminate at a connecting segment that joins the portions 559 and 560together. For example, linear or curved seam portions 559 and 560 mayterminate at a curved segment having a radius that connects the ends ofthe seams together. Similarly, seam portions 559 and 560 may terminateat a circumferentially directed segment, e.g., a line runningperpendicular to the longitudinal axis, that connects the ends of theseam together. Accordingly, the angular vertex illustrated in FIG. 50Bis provided by way of example and not limitation.

The seams herein can be formed by interfacing different segments ofmaterial in any manner, such as butt joints, overlapping portions,non-overlapping portions, etc. The sections of the steerable portion maythus be spliced together along the seams and joined using knownprocesses, such as welding or bonding using heat, adhesives, etc.

The distal most and proximal most locations of seam 558 are 180 degreesfrom another around the inner tubular member. The distal most andproximal most locations need not be defined by the intersections of twolines, but could include, for example, straight lines that areperpendicular to the longitudinal axis of the inner tubular member.

Inner tubular member 550 also includes a reinforcing member 557 alongits spine, which can be seen in FIG. 50C and shown in phantom in FIG.50B. Reinforcing member 557 extends from a proximal end secured insection 554, to a distal end secured in steerable section 553.Reinforcing member 557 is, in this embodiment, woven in secondreinforcing member 565, such as in an under-over pattern, a portion ofwhich can be seen in FIG. 50C with select cutouts. Reinforcing member557 can be woven in an under-over pattern such that it is changes itsover-under position relative to second reinforcing member 565 every timeit meets a new section of the second reinforcing member 565. In thisembodiment second reinforcing member 565 is a braided material along atleast a portion of its length. Reinforcing member 557 can alternativelybe disposed on top of or below second reinforcing member 565.Reinforcing member 557, even when woven into (e.g., any type ofover-under pattern) second reinforcing member 565, is disposed parallelto the longitudinal axis of inner tubular member 550. The distal end ofreinforcing member 557 is everted, or folds back on itself, as shown inFIG. 50C. The distal end folds back and wraps around a segment of secondreinforcing member 565, as shown in FIG. 50C. The distal end can foldback on top of, or below, the second reinforcing member 565, dependingon the relative location of the reinforcing member 557. For example, inFIG. 50C, reinforcing member 557 extends distally from under secondreinforcing member 565, and everts, or is folded back, on top of secondreinforcing member 565. The everted length can be, for example, between0.5 mm and 5 mm, such as between 1 mm and 3 mm. In some embodiments thelength of the everted length is at least 0.5 mm, such as at least 1 mm.In an embodiment, the length of the everted section is a minimum of 1.5mm. One or both ends of the reinforcing member can be everted in thismanner. In some embodiments reinforcing member 557 is not woven insecond reinforcing member 565 all of the way to the proximal end ofreinforcing member 557. For example, reinforcing member 557 can bedisposed over or under at least two braided wire portions at itsproximal end.

Everting the distal end of reinforcing member 557 provides for a moresecure anchoring of the reinforcing member 557 in the inner tubularmember 550. Accordingly, a likelihood of movement of reinforcing member557 relative to second reinforcing member 565, which could cause apredetermined shape of the steerable portion to be altered, may bereduced. The distal end of inner tubular member 550 is shown with adistal section 556, which is generally relatively flexible, and has adurometer less than second segment 552. Distal section 556 can have adurometer between 15D and 50D, such as between 25D and 45D, such as 35D.

FIG. 50D illustrates a distal region of inner tubular member 550,illustrating reinforcing member 557 disposed along the spine of theinner tubular member 550. Section A-A from FIG. 50D is shown in FIG.50E, showing inner liner 564, relatively soft distal section 556,everted distal end of reinforcing member 557, and portions of first andsecond segments 551 and 552.

The inner and outer tubular members can be manufactured individually ina number of ways. One exemplary process is that the materials of theinner tubular member can be reflowed together on a mandrel using heatshrink tubing.

Any of the coils in the devices herein can be replaced with braidedsections of material.

FIG. 52A illustrates a portion of exemplary steerable medical device,including inner tubular member 550, outer tubular member 580, which canbe the same or similar to the outer tubular member shown in FIGS.48A-48D, and distal flexible section 582. FIGS. 52B and 52C illustratesections A-A and B-B, respectively, shown in FIG. 52A. FIG. 52Cillustrates inner tubular member 550, outer tubular member 580, andreinforcing member 557 of the inner tubular member being 180 degreesopposite the midpoint of the higher durometer segment, 581, in outertubular member 580. In this design, and as described repeatedlythroughout herein, the spines of the inner and outer tubular member areoffset by 180 degrees. The relatively lower durometer material, segment583, extends more than 180 degrees around outer tubular member.

FIG. 52D shows Detail A from FIG. 52B, showing the distal end of thesteerable medical device. Inner tubular member 550 extends slightlyfurther distally than outer tubular member 580 as shown, and both engagedistal flexible tip 582.

FIG. 53A is perspective view of an exemplary steerable medical device,including external handle and actuator. FIG. 53B is an exploded view ofDetail A shown in FIG. 53A.

FIG. 53A shows, an exemplary external controller, in the form of ahandle, that is adapted to deploy and actuate the steerable devicesdescribed herein. The external controller 5300 is adapted, or can beadapted to control other steerable devices not specifically describedherein. In an embodiment, the external controller 5300 controls steeringof an exemplary steerable sheath system 1000 that includes steerabletubular members, such as those described above. Steerable sheath system1000 may be actuated by handle portion 1200.

Referring to FIG. 53B, an exploded view of handle portion 1200 is shownin accordance with an embodiment. Handle portion 1200 includes sheathflexure adjustment knob 1210, grip 1220, and guide wire port 1230.Portions of handle portion 1200 are indicated by similar numerals tothose described above with respect to FIGS. 39-41 to indicate similarfunctionality of the components, however, the portions may includestructural differences. For example, guide wire port 1230 may beintegral to a valve cap 5302 that forms a proximal end of externalcontroller 5300. Guide wire port 1230 may be internal to the controller,however. For example, guide wire port 1230 may include an embossedcylindrical portion extending between grip portions 1220 to direct aguidewire toward guide wire seal 1250 within handle portion 1200.Adjustment knob 1210, grip 1220, and guide wire port 1230 may form ahousing to contain an actuation mechanism of external controller 5300 asdescribed below.

Flexure, or steering, of the steerable sheath is facilitated by anactuation mechanism. More particularly, the actuation mechanism may beactuated by twisting control knob 1210 relative to handle grip 1220.Rotation of knob 1210 may in turn load portions that are respectivelyattached to outer shaft 1110 and inner shaft 1120 to cause relativemovement between the tubular members. The method of steering thesteerable medical devices herein using external controller 5300 may besimilar to the methods described above with respect to FIGS. 39-41, andany suitable construction of the external controller from FIGS. 39-41,or methods of using it, may be part of external controller 5300, and itsmethod of use.

In an embodiment, the amount of flexure of the sheath is related to theamount of rotation of adjustment knob 1210. In some embodiments therewill be a relatively linear correspondence between the degrees ofrotation of control knob 1210 and the angle of flexure for the sheathsteerable section. In such an embodiment each unit of incrementalrotation of the control knob 1210 substantially equals or “maps” into acorresponding and constant unit of incremental flexure for the sheathsteerable portion, independent of the starting flexure of the steerablesheath. In alternate embodiments there can be a nonlinearcorrespondence. For example, in an exemplary configuration when thesteerable section is at minimal flexure, control knob 1210 can imparttwice as much flexure as when it is at about 50% of its allowableflexure.

A portion of external controller 5300 coupled to outer sheath 1110 mayinclude an outer sheath interface tube 1340. Outer sheath 1110 may beanchored to the outer sheath interface tube at 1340, e.g., viaadhesives, ultrasonic welding, heat staking, or other suitable ways.Outer sheath 1110 and outer sheath interface tube 1340 are, in thisembodiment, axially fixed relative to grip 1220.

A portion of external controller 5300 connected to inner sheath 1120 mayinclude an inner sheath interface tube 1370. Inner sheath 1120 may beanchored to inner sheath interface tube 1370 via any of the mechanismsdescribed for the outer sheath. For example, the inner sheath interfacetube 1370 may be adhesively bonded to inner sheath 1120 at a locationproximal to a bond between outer sheath interface tube 1340 and outershaft 1110. The inner sheath interface tube 1370 is secured to drivescrew 1310. O-ring cap 5306 is secured to the proximal end of innersheath interface tube 1370 by any suitable coupling mechanism, and withO-ring 5304 disposed therebetween. Pins 5308 are positioned inside drivescrew 1310 and secure O-ring cap 5306, and thus inner sheath interfacetube 1370, to drive screw 1310. The drive screw 1310, inner sheathinterface tube 1370, and inner sheath 1120 therefore move axiallytogether. Furthermore, drive screw 1310 is axially movable relative tohandle grip 1220. Accordingly, in an embodiment, relative movementbetween outer shaft 1110 and inner shaft 1120 is effected through themovement of inner shaft 1120 relative to the handle, although handle canbe modified to work in different ways to cause steering.

It will now be apparent that relative movement between shafts to effectsteering may depend on relative movement between the respective portionsof external controller 5300 that connect to outer shaft 1110 and innershaft 1120. That is, relative movement between the shafts may beeffected by relative linear motion between inner sheath interface tube1370 and outer sheath interface tube 1340. In an embodiment, suchrelative linear motion is caused by rotation of knob actuator 1210,which causes rotation of drive nut 1330, which causes linear motion ofdrive screw 1310. More particularly, drive nut 1330 may engage knob 1210such that rotation of knob 1210 produces rotation of drive nut 1330. Inan embodiment, the rotation of knob 1210 and drive nut 1330 is in a 1:1relationship, i.e., knob 1210 is fixed to drive nut 1330. Thus, controlknob 1210 may sit over drive nut 1330 and may be constrained againstrotation relative to the drive nut 1330. Control knob 1210 and drive nut1330 may in turn be positioned concentrically around drive screw 1310and inner sheath interface tube 1370, and outer sheath interface tube1340 may sit concentrically within the drive nut 1330.

In an embodiment, drive nut 1330 may be placed in a threaded engagementwith drive screw 1310. That is, an internal thread of drive nut 1330 maymesh with an external thread of drive screw 1310. Since inner sheathinterface tube 1370 is axially movable relative to handle 1220, rotationof knob 1210 produces linear motion of drive nut 1330 and inner sheathinterface tube 1370, and thus the inner sheath. Handle extensions 1320(e.g., pins) ride in the drive screw slot 1350, as described above, andprevent the drive screw from rotation when the knob 1210 is rotated. Thehandle extensions thus cause the axial movement of drive screw 1310,which causes axial movement of the inner sheath. Axial movement of outersheath interface tube 1340 is prevented, relative to handle grip 1220,by handle extensions 1320 (e.g., pins), which extends into an aperturein the proximal end of outer sheath interface tube 1340. The position ofouter sheath interface tube 1340 and thus the outer sheath are axiallyfixed relative to handle grip 1220. Actuation of actuator 1210 thus, inthis embodiment, axially moves the inner sheath but does not cause axialmovement of the outer sheath. In some embodiments the externalcontroller is adapted such that, upon actuation, the outer tubularmember moves axially but the inner tubular member does not.

FIGS. 54A-54C illustrate an exemplary outer tubular member 620 of asteerable medical device. Outer tubular member 620 can be built into anyof the steerable medical devices herein, and can be used with any of theinner tubular members herein, or any of the handle assemblies herein. Insome embodiments a steerable medical device includes outer tubularmember 620 and inner tubular member 550 shown in FIGS. 50A-50E. In someregards outer tubular member 620 is similar to the outer tubular membershown and described with respect to 48A-48D herein, but there aredifferences between the two exemplary embodiments.

Outer tubular member 620 includes a steerable portion 622, whichincludes first segment 623 and second segment 624. First segment 623 hasa higher durometer than second segment 624. First segment 623 acts as aspine along steerable portion 624. In some embodiments first segment 623has a durometer between 45D and 90D, such as between 55D and 85D, suchas between 65D and 80D (e.g., 72D Pebax), and second segment 624 has adurometer between 20D and 50D, such as between 25D and 45D (e.g., 35DPebax). First segment 623 extends less than 180 degrees around the outertubular member, and second segment 624 extends more than 180 degreesaround the outer tubular member. The joints between the two segments areparallel to the longitudinal axis of the outer tubular member. In otherembodiments, however, the joints between segments 623 and 624 can benon-parallel to the longitudinal axis of the outer tubular member, andmay also be non-perpendicular to the longitudinal axis of the outertubular member. For example, any portion of the joint (or seam) betweensegments 623 and 624 can be angled as described above with respect toinner tubular member 550. Outer tubular member 620 includes atransitional proximal portion 625, which may have a durometer betweenabout 50D and 90D, such as between 60D and 80D (e.g., 72D Pebax). Outertubular member 620 also includes relatively longer proximal portion 626,which may extend all the way to a handle assembly, such as any of thehandle assemblies described herein. More particularly, proximal portion626 may extend to a proximal end of outer tubular member 620. In amerely exemplary embodiment proximal portion 626 is a polyamide, e.g.,Vestamid, material.

FIG. 54B illustrates a view taken through Section H-H shown in FIG. 54A.

FIG. 54C shows detail F shown in FIG. 54A, which is a distal region ofouter tubular member 620. Distal to steerable portion 622 is a section627, which may be shorter than steerable portion 622, and distal tosection 627 is distal tip 628. FIG. 54C also shows that outer tubularmember 620 also includes optional reinforcing member 631 (in thisembodiment a Kevlar strip) and second reinforcing member 632 (in thisembodiment a braided material). The reinforcing strip may have across-sectional geometry having uniform cross-sectional dimensions ornon-uniform cross-sectional dimensions. For example, the cross-sectionalgeometry may be circular, such that the cross-sectional dimension is auniform diameter. Alternatively, the cross-sectional geometry may berectangular or elliptical, such that the cross-sectional dimensionsinclude a width greater than a height, or vice versa. Accordingly, thecross-sectional geometry may result in higher reinforcement in onedirection, e.g., in the direction of a horizontal axis of the strip,than in another direction, e.g., in the direction of a vertical axis ofthe strip. Reinforcing member 631 is disposed within the spine of outertubular member 620, and specifically within first segment 623.Reinforcing member 631 extends axially (parallel to a longitudinal axisof outer tubular member 620) and through a midpoint of first segment623. Alternatively stated, a plane containing reinforcing member 631 anda central axis of outer tubular member 620 may divide first segment 623into two hypothetical symmetrical sections. In some embodimentsreinforcing member 631 is a Kevlar line.

Reinforcing member 631 can help prevent unwanted stretching of the outertubular member spine (e.g., segment 623) if it is placed under tensionduring bending. For example, if outer tubular member 620 is placed undertension via a handle assembly to steer the steerable section, firstsegment 623 may stretch more than desired, resulting in an increase inthe travel of the outer tubular member in the handle to steer thesteerable section. The unwanted stretching can thus lead to inefficientsteering by increasing the travel needed to steer the steerable portionto the desired configuration. Reinforcing member 631 in the spine ofouter tubular member can reduce the stretching, and thus the travel, andthus can increase the efficiency of the bending. In some embodiments thesteerable system may be adapted to put outer tubular member 623 only incompression, and it may not be necessary to include reinforcing member631. Alternatively, even in systems where the inner tubular member isput under tension, it may not be necessary to include reinforcing member631.

Reinforcing member 631 can be woven through second reinforcing member632 (e.g., a braided material) in any desired pattern. Either of theends of reinforcing member 631 can be everted such as described above.More particularly, either end of the reinforcing member 631 may befolded on itself, however, in this embodiment neither end is everted.

The ends of reinforcing member 631 can be disposed over or under secondreinforcing member 632 along at least one wire. For example, in anembodiment, a distal end of reinforcing member 631 is woven between thebraided material and coincides with a distal end of the braidingmaterial. Furthermore, the reinforcing member 631 may extend to a distalend of the outer tubular member 620. More particularly, the distal endof the reinforcing member 631 may be located within a bonding regionwhere the distal end of the outer tubular member 620 is bonded to theinner tubular member 550. Locating the distal end of the reinforcingmember 631 within this bonding region may minimize stretching of theouter tubular member 620 in some actuation modes, and thus, may reducethe range of travel of the controller 650 required to achieve aparticular steering bend.

A proximal end of reinforcing member 631 may overlap the wires of thebraided material. More particularly, the proximal end portiontransitions from a triaxial braid configuration to overlap either anoutside surface or an inside surface of the wires. This is similar tothe manner of overlap described above with respect to an embodiment ofinner tubular member 550 above. More particularly, an end section of thereinforcing member 631 may overlay or underlay at least one turn of eachbraid wire.

The distal end of reinforcing member 631 extends into distal tip section628 of outer tubular member 620, and can extend all the way to the endof the distal tip section 628. In some embodiments the distal end ofreinforcing member 631 is in section 627. The proximal end ofreinforcing member 631 is disposed proximal to steerable portion 622,and in this embodiment is disposed in transition section 625.

In this embodiment liner 633 does not extend to the distal end of outertubular member 620. Specifically, liner 633 extends to the distal end ofsection 627, but not into tip section 628.

Distal tip section 628, from inside to outside, includes inner layer630, a layer that includes both reinforcing members 631 and 632 (631woven in 632 along at least a portion of tip section 628), marker band629, and outer layer 635. In some embodiments inner layer 630 can have adurometer from 20D to 50D, such as 30D to 40D (e.g., 35D). In someembodiments outer layer 635 has a durometer from 40D to 70D, such as 45Dto 65D (e.g., 55D).

In some embodiments the inner and outer tubular members have linearreinforcing members (e.g., Kevlar lines), and are 180 degrees apart. Thereinforcing members can be aligned with spines of both inner and outertubular members.

FIG. 55A illustrates a portion of an exemplary steerable medical device645, including inner tubular member 550, outer tubular member 620, andflexible distal tip 640. FIG. 55B shows section W-W shown in FIG. 55A.FIG. 55C shows section Z-Z shown in FIG. 55B, and FIG. 55D shows detailA-A of the distal end shown in FIG. 55C. As shown in FIG. 55B, thereinforcing members 631 and 557 are 180 degrees from each other.Reinforcing member 557 of the inner tubular member is 180 degrees fromthe midpoint of the higher durometer segment, 623, in outer tubularmember 620. FIG. 55C illustrates distal tip 640 secured to outer tubularmember 620 and inner tubular member 550, which are also secured to oneanother. FIG. 55D highlights the bonded nature of inner tubular member550 and outer tubular member 620, and flexible distal tip 640. Innertubular member 550 extends further distally than outer tubular member620, and both are secured to distal flexible tip 640. More particularly,inner tubular member 550, outer tubular member 620, and distal flexibletip 640 may be fused together using, e.g., a heat fusing process, toform steerable medical device 645.

A distal end of reinforcing member 631 may coincide with a distal end ofouter tubular member 620. For example, the distal end of reinforcingmember 631 can have a same axial location or extent as a distal end ofouter tubular member 620. In an embodiment, the distal end ofreinforcing member 631 is within the bond region formed by fusing theinner tubular member 550, the outer tubular member 620, and the distalflexible tip 640.

FIGS. 56A-H illustrate an exemplary external controller 650 that isadapted to steer a steerable medical device, optionally any of thesteerable devices herein that include first and second tubular members,such as steerable medical device 645 that includes outer tubular member620 and inner tubular member 550. The steerable medical device caninclude any of the inner and outer tubular members herein, including anycombination thereof.

FIG. 56A is a perspective view showing the assembled assembly, includingexternal controller 650 secured to steerable device 645. FIG. 56B showsan exploded view of external controller, which includes an actuator grip651 (e.g., rotatable knob), actuator nut 652, drive screw 653 includingtwo wings 660 extending radially from the screw, valve body 654 (andoptionally a stopcock tethered to the valve body 654 and placed in fluidcommunication with the valve body 654 by a tubular flush line), handleshells or grips 655 each including a slot 661, valve 656, valve cap 657,friction members 658, and bearing 659. Also shown are outer tubularmember 620 and inner tubular member 550.

FIG. 56C shows an assembled view of controller but with one handle shellremoved, and compared to FIG. 56B would be considered a bottom view withbottom handle shell 655 removed. FIG. 56D shows a sectional view 90degrees relative to the view in 56C. FIG. 56E is a sectional view of theview from 56C. FIGS. 56F-H show highlighted views of portions of thecontroller from the sectional view from FIG. 56E. FIG. 56F shows acentral region, FIG. 56G shows a proximal region, and FIG. 56H shows adistal region of external controller.

In this embodiment the proximal end of inner tubular member 550 issecured directly to valve body inside a channel in valve body 654. Outertubular member 620 is secured within a distal region of drive screw 653.Distal movement of drive screw 653 pushes on outer tubular member andputs it in compression, and because the tubular members are axiallyfixed distal to the steerable portion, inner tubular member is put undertension. Proximal movement of drive screw 653 pulls on outer tubularmember 620, putting it in tension, which puts the inner tubular memberin compression. Distal movement of drive screw 653 causes the steerabledevice 645 to steer in a first direction, while proximal movement ofdrive screw 653 causes the steerable device 645 to bend in a seconddirection. In embodiments in which the tubular members have spines thatare 180 degrees apart (such as with tubular members 550 and 620), thetwo bending directions are in the same plane, 180 degrees apart. Innertubular member 550 is disposed within drive screw 653 and drive screw653 can move axially relative to inner tubular member 550.

In an embodiment, drive screw 653 extends proximally from outer tubularmember 620 and surrounds at least a portion of inner tubular member 550between a proximal end of outer tubular member 620 and valve body 654.As such, drive screw 653 provides column support to inner tubular member550 by limiting transverse deflection of inner tubular member 550. Moreparticularly, when inner tubular member 550 is placed in compression, itmay have a tendency to buckle, however, drive screw 653 around innertubular member 550 may prevent such buckling. Thus, drive screw 653 mayserve dual functions as both a force transmission element to convertrotational motion of the actuator nut 652 into axial motion of outertubular member 620, and an anti-buckling element to prevent buckling ofinner tubular member 550 during steering.

In this embodiment axial movement of drive screw 653 is caused byactuation of actuator grip 651, and in this embodiment, rotation ofactuator grip 651. Actuator grip 651 is secured to nut 652, such thatrotation of actuator grip 651 causes nut 652 to rotate as well. Actuatorgrip 651 is a gripping element that facilitates the rotation of nut 652.Nut 652 has an internal interfacing element that interfaces with theouter thread of drive screw 653. In an embodiment, the internalinterfacing element of nut 652 is a single thread, i.e., a thread havinga single turn, to engage the thread of drive screw 653. Thus, the lengthof threaded contact between nut 652 and drive screw 653 is fewer thanten turns, e.g., fewer than five turns, in an embodiment. In anembodiment, the threaded interface occurs at a central region 670 ofdrive screw 653. Additionally, drive screw 653 includes two wings 660(or pins) that are 180 degrees part, each of which extends radially fromthe body of the screw and rides in a separate slot 661 of handle grips655. The interface between the wings and the slots prevents the drivescrew 653 from rotating when actuator grip 651 is rotated. When actuatorgrip 651 is rotated, the internal interfacing element of nut 652 rotatesrelative to the thread of drive screw 653, the interface between wings660 and slots 661 prevents the drive screw from rotating, and the drivescrew 653 will move axially, either proximally or distally, depending onthe direction of rotation of actuator grip 651. The ability to bend thesteerable device 645 in two directions is referred to generally hereinas bi-directional steerability, which external controller 650 provides.

The interfacing location 670 between the nut 652 and drive screw 653 isrelevant to the bi-directional steerability. Because the interface is ina central region of the thread (i.e., not at an extreme end of thethread of the drive screw), rotation of actuator grip 651 in bothdirections causes axial movement of drive screw 653 (either distally oraxially depending on the direction or rotation). This puts the outertubular member in either compression or tension (depending on thedirection of rotation), which puts the inner tubular member in the otherof compression and tension, and under either scenario the steerabledevice is steered, but not necessarily in the same direction, e.g., inopposite directions.

By allowing the drive screw to move in both directions (such as byinterfacing the thread at a central region), bi-directionality can beachieved. Interfacing the thread at the extreme distal or proximal endmay allow the drive screw to travel in only one direction, and wouldthus remove the bi-directionality of the device. As long as theinterface is at a location that allows for some axial movement in bothdirections (even if just very little axial movement in one direction),bi-directionality can be achieved. By changing the location 670 of theinterface between drive screw 653 and nut 652 (away from exact center ofthread of the drive screw), a bias can be put in the steerable device,such that it can be steered more in one direction than the other. Forexample, if range of travel of drive screw 653 is greater in a certainaxial direction, i.e., either distally or proximally, a range ofsteering may be greater in a corresponding direction, e.g., steerabledevice 645 may curve more in one direction than another. If there is abias, however, bi-directionality would still be achieved.

In an embodiment, a direction of steering may be aligned with the flushline extending from the valve body 654. Steering may be within a planecontaining a central axis of the steerable device 645. That is,deflection of steerable device 645 may result in steering within theplane to one side or another of the central axis. Since such steeringordinarily occurs while the steerable device 645 is located in a patientanatomy, however, it may difficult for a physician to ascertain theorientation of the steerable device 645 relative to the controller 650outside of the patient anatomy. To compensate for this, the flush linemay extend laterally from a side wall of the valve body 654 in adirection within the plane of steering. Thus, the physician maydetermine a relative orientation between the flush line outside of theanatomy and the distal end of steerable device 645 inside the anatomy topredict a direction of steering inside the anatomy.

In some embodiments the actuator grip 651 and nut 652 could be integral,such that they can be considered the same part (e.g., together an“actuator”). For example, actuator grip 651 may be a rubber componentovermolded on the nut 652 to form an integrated, two-part body.

Controller 650 also includes valve 656, which is held in place whenvalve cap 657 is secured to valve body 654. More particularly, valve 656may be compressed between valve cap 657 and valve body 654. Valve 656may, for example, include a slit diaphragm, and thus, such compressionmay maintain an integrity of the slit diaphragm to prevent leaking. Forexample, the compressed diaphragm may prevent blood from leaking throughvalve 656, and thus, valve 656 may maintain hemostasis of the controller650. Nonetheless, the slit diaphragm of valve 656 may permit passage ofa working device, e.g., a guidewire, through valve 656, controller 650,and steerable device 645. Actuator grip 651 and nut 652 can be securedtogether using any number of known techniques. Actuator grip 651 can bea soft material such as rubber that slides over nut 652, with internalfeatures on the inside of actuator grip 651 that interface with externalfeatures of nut 652 (see FIG. 56H). When actuator grip 651 and nut 652are not integral (such as in this embodiment), torque may be transmittedfrom actuator grip 651 to nut 652. Distal end of nut 652 has a pluralityof female components (see FIG. 56B) that interface with male componentson the inside of actuator grip 651, and the interface transmits torque.For example, the male components may include radial fins extendinglaterally from an inner surface of actuator grip 651, and the fins mayengage corresponding slots formed through an outer wall of nut 652.Accordingly, the keyed relationship between the fins and the slots mayallow for rotation of actuator grip 651 to transmit a rotational forcefrom the fins to the slots to cause a corresponding rotation of nut 652.

Bearing 659 may include a flattened ring, such as a washer profile, toprevent contact between nut 652 and shells 655. Accordingly, bearing 659may reduce friction between nut 652 and handle shells 655. This providesfor ease of rotation of actuator grip 651 and smooth actuation ofsteerable device 645.

Friction members 658 may be o-rings that act as frictional elements toprovide smooth friction, and are disposed in slots in the handle shells.More particularly, the friction members 658 may include an outer surfaceto slide against handle shells 655 and an inner surface to slide againstnut 652 to provide an increased and repeatable surface contact andfrictional force between those elements. Accordingly, friction members658 can reduce or prevent backlash.

In some embodiments the proximal end of outer tubular member is disposedinside the drive screw less than 2 inches from the distal end of thedrive screw, and can be secured in place relative to the drive screwwith glue injected into a glue port or a glue hole in the drive screw.In some embodiment the proximal end of the inner tubular member 550extends 1 mm to 200 mm further proximally that the proximal end of theouter tubular member 620.

What is claimed is:
 1. A steerable medical device, comprising: an innerflexible tubular member with a polymeric inner spine of a first materialextending along a length of a steerable portion and having a durometergreater than a second segment material extending along the length of thesteerable portion; an outer flexible tubular member axially fixed to theinner flexible tubular member at a fixation location distal to thesteerable portion, the outer tubular member having a polymeric outerspine that is offset from the inner spine having a linear segment of afirst material extending less than 180 degrees around the outer tubularmember and having a durometer greater than a second segment materialextending more than 180 degrees around the outer tubular member, alinear reinforcing member extending within at least one of the firstmaterial of a greater durometer of said polymeric inner spine or thefirst material of a greater durometer of said polymeric outer spine; andan external controller operatively interfacing with the inner and outerflexible tubular members to put one of the inner and outer tubularmembers in tension and the other in compression, to steer the steerableportion.
 2. The steerable medical device of claim 1 wherein the linearreinforcing member is respectively extending within both the polymericinner spine and the polymeric outer spine.
 3. The steerable medicaldevice of claim 1 wherein linear reinforcing member is 180 degrees awayfrom the polymeric inner spine around the steerable medical device. 4.The steerable medical device of claim 1 wherein the outer tubular memberfurther comprises a braided reinforcing member in the steerable portion.5. The steerable medical device of claim 1 wherein a distal end of thelinear reinforcing member is further distally than a distal end of thesteerable portion.
 6. The steerable medical device of claim 1 wherein adistal end of the linear reinforcing member extends to a location wherethe inner tubular member and outer tubular member are axially securetogether.
 7. The steerable medical device of claim 2 wherein the linearreinforcing member of the polymeric outer spine and the linearreinforcing member of the polymeric inner spine are 180 degrees awayfrom each other around the steerable medical device.
 8. The steerablemedical device of claim 4 wherein the linear reinforcing member is woveninto the braided reinforcing member.
 9. The steerable medical device ofclaim 5 wherein a distal end of the linear reinforcing member extendssubstantially to a distal end of the outer tubular member.